diff --git a/backend/app/api/composites.py b/backend/app/api/composites.py
new file mode 100644
index 0000000..53820db
--- /dev/null
+++ b/backend/app/api/composites.py
@@ -0,0 +1,69 @@
+"""因子组合 API（M7.2b）：/api/composites CRUD。
+
+组合 = 可复用因子权重集；计算时方向取因子注册表，落库冗余快照。
+"""
+
+from __future__ import annotations
+
+from fastapi import APIRouter, HTTPException
+
+from app.api.deps import CompositeRepoDep, DbSession
+from app.application.services.job_executor import new_id
+from app.domain.entities.composite import CompositeComponent, CompositeDefinition
+from app.quant.factors import FactorError, get_factor
+
+router = APIRouter(prefix="/composites", tags=["composites"])
+
+
+def _fill_direction(definition: CompositeDefinition) -> CompositeDefinition:
+    """以因子注册表元数据补齐/校正组件 direction（登记但不可计算的因子报错）。"""
+    out = []
+    for c in definition.components:
+        try:
+            defn, _fn = get_factor(c.name)
+        except FactorError as exc:
+            raise HTTPException(status_code=400, detail=str(exc)) from exc
+        out.append(CompositeComponent(name=c.name, weight=c.weight, direction=defn.direction))
+    return definition.model_copy(update={"components": out})
+
+
+@router.post("", summary="保存因子组合", response_model=CompositeDefinition)
+def create_composite(
+    definition: CompositeDefinition,
+    composite_repo: CompositeRepoDep,
+    session: DbSession,
+) -> CompositeDefinition:
+    prepared = _fill_direction(definition.model_copy(update={"id": ""}))
+    try:
+        saved = composite_repo.save(
+            prepared.model_copy(update={"id": new_id("CF")})
+        )
+        session.commit()
+        return saved
+    except ValueError as exc:
+        raise HTTPException(status_code=400, detail=str(exc)) from exc
+
+
+@router.get("", summary="因子组合列表", response_model=list[CompositeDefinition])
+def list_composites(composite_repo: CompositeRepoDep) -> list[CompositeDefinition]:
+    return composite_repo.list()
+
+
+@router.get("/{composite_id}", summary="读取因子组合", response_model=CompositeDefinition)
+def get_composite(composite_id: str, composite_repo: CompositeRepoDep) -> CompositeDefinition:
+    row = composite_repo.get(composite_id)
+    if row is None:
+        raise HTTPException(status_code=404, detail=f"组合 {composite_id} 不存在")
+    return row
+
+
+@router.delete("/{composite_id}", summary="删除因子组合")
+def delete_composite(
+    composite_id: str,
+    composite_repo: CompositeRepoDep,
+    session: DbSession,
+) -> dict:
+    if not composite_repo.delete(composite_id):
+        raise HTTPException(status_code=404, detail=f"组合 {composite_id} 不存在")
+    session.commit()
+    return {"deleted": composite_id}
diff --git a/backend/app/api/deps.py b/backend/app/api/deps.py
index fd52565..bb75a53 100644
--- a/backend/app/api/deps.py
+++ b/backend/app/api/deps.py
@@ -11,6 +11,7 @@ from fastapi import Depends
 from sqlalchemy.orm import Session
 
 from app.application.services.selection_service import SelectionService
+from app.domain.repositories.composite import CompositeRepository
 from app.domain.repositories.factor import FactorRepository
 from app.domain.repositories.jobs import ExperimentRepository, JobRepository
 from app.domain.repositories.market import (
@@ -19,6 +20,9 @@ from app.domain.repositories.market import (
     StockRepository,
 )
 from app.domain.repositories.selection import SelectionRepository
+from app.infrastructure.persistence.sqlalchemy.repositories.composite_impl import (
+    SqlAlchemyCompositeRepository,
+)
 from app.infrastructure.persistence.sqlalchemy.repositories.factor_impl import (
     SqlAlchemyFactorRepository,
 )
@@ -78,6 +82,10 @@ def _factor_repo_factory(session: DbSession) -> FactorRepository:
     return SqlAlchemyFactorRepository(session)
 
 
+def _composite_repo_factory(session: DbSession) -> CompositeRepository:
+    return SqlAlchemyCompositeRepository(session)
+
+
 StockRepoDep = Annotated[StockRepository, Depends(_stock_repo_factory)]
 DailyRepoDep = Annotated[DailyBarRepository, Depends(_daily_repo_factory)]
 EngineDep = Annotated[QuantEngine, Depends(_engine_factory)]
@@ -85,6 +93,7 @@ ResearchServiceDep = Annotated[ResearchService, Depends(_service_factory)]
 SelectionServiceDep = Annotated[SelectionService, Depends(_selection_service_factory)]
 SelectionRepoDep = Annotated[SelectionRepository, Depends(_selection_repo_factory)]
 FactorRepoDep = Annotated[FactorRepository, Depends(_factor_repo_factory)]
+CompositeRepoDep = Annotated[CompositeRepository, Depends(_composite_repo_factory)]
 
 
 def _job_repo_factory(session: DbSession):
diff --git a/backend/app/api/router.py b/backend/app/api/router.py
index 94be253..81e4e74 100644
--- a/backend/app/api/router.py
+++ b/backend/app/api/router.py
@@ -8,12 +8,23 @@ from __future__ import annotations
 
 from fastapi import APIRouter
 
-from app.api import agent, experiments, factors, health, jobs, research, selections, stocks
+from app.api import (
+    agent,
+    composites,
+    experiments,
+    factors,
+    health,
+    jobs,
+    research,
+    selections,
+    stocks,
+)
 
 api_router = APIRouter()
 api_router.include_router(health.router)
 api_router.include_router(stocks.router)
 api_router.include_router(factors.router)
+api_router.include_router(composites.router)
 api_router.include_router(research.router)
 api_router.include_router(selections.router)
 api_router.include_router(jobs.router)
diff --git a/backend/app/domain/entities/composite.py b/backend/app/domain/entities/composite.py
new file mode 100644
index 0000000..0aeb950
--- /dev/null
+++ b/backend/app/domain/entities/composite.py
@@ -0,0 +1,33 @@
+"""因子组合（Composite Factor）领域实体（M7.2b，v2 §13）。
+
+组合 = 一组 {因子, 权重} + method（MVP fixed：截面 zscore×方向×权重求和；
+方向在计算时取因子注册表元数据，落库时冗余快照以便列表展示）。
+"""
+
+from __future__ import annotations
+
+from datetime import datetime
+
+from pydantic import BaseModel, Field, model_validator
+
+
+class CompositeComponent(BaseModel):
+    name: str
+    weight: float = Field(default=1.0, gt=0)
+    direction: str = Field(default="higher_is_better")
+
+
+class CompositeDefinition(BaseModel):
+    id: str = ""
+    name: str = Field(min_length=1, max_length=64)
+    method: str = Field(default="fixed", pattern="^(fixed)$")
+    description: str = ""
+    components: list[CompositeComponent] = Field(min_length=1)
+    created_at: datetime | None = None
+
+    @model_validator(mode="after")
+    def _no_duplicate(self) -> CompositeDefinition:
+        names = [c.name for c in self.components]
+        if len(set(names)) != len(names):
+            raise ValueError("components 存在重复因子名")
+        return self
diff --git a/backend/app/domain/repositories/composite.py b/backend/app/domain/repositories/composite.py
new file mode 100644
index 0000000..fbc3911
--- /dev/null
+++ b/backend/app/domain/repositories/composite.py
@@ -0,0 +1,19 @@
+"""Composite Factor Repository Protocol（M7.2b）。"""
+
+from __future__ import annotations
+
+from typing import Protocol
+
+from app.domain.entities.composite import CompositeDefinition
+
+
+class CompositeRepository(Protocol):
+    def save(self, definition: CompositeDefinition) -> CompositeDefinition:
+        """新建组合（name 冲突抛 ValueError）。"""
+
+    def get(self, composite_id: str) -> CompositeDefinition | None: ...
+
+    def list(self) -> list[CompositeDefinition]: ...
+
+    def delete(self, composite_id: str) -> bool:
+        """删除；不存在返回 False。"""
diff --git a/backend/app/infrastructure/persistence/migrations/versions/c3e9a0d1f4b5_factor_composite_table.py b/backend/app/infrastructure/persistence/migrations/versions/c3e9a0d1f4b5_factor_composite_table.py
new file mode 100644
index 0000000..9ae82c5
--- /dev/null
+++ b/backend/app/infrastructure/persistence/migrations/versions/c3e9a0d1f4b5_factor_composite_table.py
@@ -0,0 +1,37 @@
+"""factor_composite 表（M7.2b 因子组合保存/复用）
+
+Revision ID: c3e9a0d1f4b5
+Revises: b7f2a5e81c33
+Create Date: 2026-09-09
+
+"""
+
+from __future__ import annotations
+
+from collections.abc import Sequence
+
+import sqlalchemy as sa
+from alembic import op
+
+revision: str = "c3e9a0d1f4b5"
+down_revision: str | None = "b7f2a5e81c33"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "factor_composite",
+        sa.Column("id", sa.String(length=32), nullable=False),
+        sa.Column("name", sa.String(length=64), nullable=False),
+        sa.Column("method", sa.String(length=16), nullable=False),
+        sa.Column("description", sa.String(length=300), nullable=False),
+        sa.Column("components_json", sa.Text(), nullable=False),
+        sa.Column("created_at", sa.DateTime(), nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("name", name="uq_factor_composite_name"),
+    )
+
+
+def downgrade() -> None:
+    op.drop_table("factor_composite")
diff --git a/backend/app/infrastructure/persistence/sqlalchemy/models/__init__.py b/backend/app/infrastructure/persistence/sqlalchemy/models/__init__.py
index 345db4a..5311611 100644
--- a/backend/app/infrastructure/persistence/sqlalchemy/models/__init__.py
+++ b/backend/app/infrastructure/persistence/sqlalchemy/models/__init__.py
@@ -4,6 +4,9 @@
 模型统一继承 infra.persistence.sqlalchemy.base.Base。
 """
 
+from app.infrastructure.persistence.sqlalchemy.models.composite import (  # noqa: F401
+    FactorCompositeModel,
+)
 from app.infrastructure.persistence.sqlalchemy.models.factor import (  # noqa: F401
     FactorDefinitionModel,
 )
diff --git a/backend/app/infrastructure/persistence/sqlalchemy/models/composite.py b/backend/app/infrastructure/persistence/sqlalchemy/models/composite.py
new file mode 100644
index 0000000..f1d88fb
--- /dev/null
+++ b/backend/app/infrastructure/persistence/sqlalchemy/models/composite.py
@@ -0,0 +1,25 @@
+"""因子组合表（M7.2b）。
+
+factor_composite：可保存/复用的因子组合定义；components 以 JSON 存
+（组件方向冗余快照自因子注册表，计算时以注册表为准）。
+"""
+
+from __future__ import annotations
+
+from datetime import datetime
+
+from sqlalchemy import DateTime, String, Text
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.infrastructure.persistence.sqlalchemy.base import Base
+
+
+class FactorCompositeModel(Base):
+    __tablename__ = "factor_composite"
+
+    id: Mapped[str] = mapped_column(String(32), primary_key=True)
+    name: Mapped[str] = mapped_column(String(64), unique=True)
+    method: Mapped[str] = mapped_column(String(16), default="fixed")
+    description: Mapped[str] = mapped_column(String(300), default="")
+    components_json: Mapped[str] = mapped_column(Text)
+    created_at: Mapped[datetime] = mapped_column(DateTime)
diff --git a/backend/app/infrastructure/persistence/sqlalchemy/repositories/composite_impl.py b/backend/app/infrastructure/persistence/sqlalchemy/repositories/composite_impl.py
new file mode 100644
index 0000000..31ba0a8
--- /dev/null
+++ b/backend/app/infrastructure/persistence/sqlalchemy/repositories/composite_impl.py
@@ -0,0 +1,80 @@
+"""因子组合 Repository 的 SQLAlchemy 实现（M7.2b）。"""
+
+from __future__ import annotations
+
+import json
+from datetime import datetime
+
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+
+from app.domain.entities.composite import CompositeComponent, CompositeDefinition
+from app.infrastructure.persistence.sqlalchemy.models.composite import FactorCompositeModel
+
+
+class SqlAlchemyCompositeRepository:
+    def __init__(self, session: Session) -> None:
+        self._session = session
+
+    def save(self, definition: CompositeDefinition) -> CompositeDefinition:
+        if not definition.id:
+            raise ValueError("需要 id（由调用方生成）")
+        exists = self._session.get(FactorCompositeModel, definition.id)
+        dup = self._session.scalar(
+            select(FactorCompositeModel)
+            .where(FactorCompositeModel.name == definition.name)
+            .limit(1)
+        )
+        if dup is not None and dup.id != definition.id:
+            raise ValueError(f"组合名已存在：{definition.name}")
+        now = definition.created_at or datetime.now()
+        if exists is None:
+            self._session.add(
+                FactorCompositeModel(
+                    id=definition.id,
+                    name=definition.name,
+                    method=definition.method,
+                    description=definition.description,
+                    components_json=json.dumps(
+                        [c.model_dump() for c in definition.components], ensure_ascii=False
+                    ),
+                    created_at=now,
+                )
+            )
+        else:
+            exists.name = definition.name
+            exists.method = definition.method
+            exists.description = definition.description
+            exists.components_json = json.dumps(
+                [c.model_dump() for c in definition.components], ensure_ascii=False
+            )
+        self._session.flush()
+        return definition
+
+    def get(self, composite_id: str) -> CompositeDefinition | None:
+        row = self._session.get(FactorCompositeModel, composite_id)
+        return _to_entity(row) if row else None
+
+    def list(self) -> list[CompositeDefinition]:
+        rows = self._session.scalars(
+            select(FactorCompositeModel).order_by(FactorCompositeModel.name)
+        ).all()
+        return [_to_entity(r) for r in rows]
+
+    def delete(self, composite_id: str) -> bool:
+        row = self._session.get(FactorCompositeModel, composite_id)
+        if row is None:
+            return False
+        self._session.delete(row)
+        return True
+
+
+def _to_entity(row: FactorCompositeModel) -> CompositeDefinition:
+    return CompositeDefinition(
+        id=row.id,
+        name=row.name,
+        method=row.method,
+        description=row.description,
+        components=[CompositeComponent(**c) for c in json.loads(row.components_json)],
+        created_at=row.created_at,
+    )
diff --git a/backend/tests/test_composites_api.py b/backend/tests/test_composites_api.py
new file mode 100644
index 0000000..06a04d8
--- /dev/null
+++ b/backend/tests/test_composites_api.py
@@ -0,0 +1,125 @@
+"""M7.2b 因子组合测试：repo CRUD（幂等/去重）+ /api/composites（含方向填充/404/删除）。"""
+
+from __future__ import annotations
+
+import pytest
+from app.api import deps
+from app.domain.entities.composite import CompositeComponent, CompositeDefinition
+from app.infrastructure.persistence.sqlalchemy.base import Base
+from app.infrastructure.persistence.sqlalchemy.repositories.composite_impl import (
+    SqlAlchemyCompositeRepository,
+)
+from app.main import app
+from fastapi.testclient import TestClient
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+
+
+@pytest.fixture()
+def session(tmp_path):
+    engine = create_engine(f"sqlite:///{tmp_path / 'c.db'}", future=True)
+    Base.metadata.create_all(engine)
+    Session = sessionmaker(bind=engine, expire_on_commit=False)
+    with Session() as s:
+        yield s
+
+
+def _comp(name="质量动量", **kw) -> CompositeDefinition:
+    base = dict(
+        name=name,
+        description="测试组合",
+        components=[
+            CompositeComponent(name="momentum_60", weight=0.7, direction="higher_is_better"),
+            CompositeComponent(name="volatility_60", weight=0.3, direction="lower_is_better"),
+        ],
+    )
+    base.update(kw)
+    return CompositeDefinition(**base)
+
+
+class TestCompositeRepository:
+    def test_save_get_list(self, session) -> None:
+        repo = SqlAlchemyCompositeRepository(session)
+        saved = repo.save(_comp().model_copy(update={"id": "CF-TEST-1"}))
+        session.commit()
+        assert saved.id == "CF-TEST-1"
+        got = repo.get("CF-TEST-1")
+        assert got is not None and got.name == "质量动量"
+        assert len(got.components) == 2
+        assert repo.list()[0].components[0].direction == "higher_is_better"
+
+    def test_duplicate_name_rejected(self, session) -> None:
+        repo = SqlAlchemyCompositeRepository(session)
+        repo.save(_comp().model_copy(update={"id": "CF-A"}))
+        session.commit()
+        with pytest.raises(ValueError):
+            repo.save(_comp().model_copy(update={"id": "CF-B"}))  # 同名不同 id
+
+    def test_delete(self, session) -> None:
+        repo = SqlAlchemyCompositeRepository(session)
+        repo.save(_comp().model_copy(update={"id": "CF-X"}))
+        session.commit()
+        assert repo.delete("CF-X") is True
+        session.commit()
+        assert repo.get("CF-X") is None
+        assert repo.delete("CF-X") is False
+
+
+@pytest.fixture()
+def client(tmp_path):
+    engine = create_engine(f"sqlite:///{tmp_path / 'api.db'}", future=True)
+    Base.metadata.create_all(engine)
+    Session = sessionmaker(bind=engine, expire_on_commit=False)
+
+    def _session_override():
+        with Session() as s:
+            yield s
+
+    app.dependency_overrides[deps.get_session] = _session_override
+    with TestClient(app) as c:
+        yield c
+    app.dependency_overrides.clear()
+
+
+class TestCompositesApi:
+    def test_crud(self, client) -> None:
+        body = {
+            "name": "质量动量组合",
+            "description": "动量+低波",
+            "components": [
+                {"name": "momentum_60", "weight": 0.7},
+                {"name": "volatility_60", "weight": 0.3},
+            ],
+        }
+        created = client.post("/api/composites", json=body)
+        assert created.status_code == 200
+        cid = created.json()["id"]
+        assert cid.startswith("CF-")
+        # 方向由注册表自动填充
+        dirs = {c["name"]: c["direction"] for c in created.json()["components"]}
+        assert dirs == {"momentum_60": "higher_is_better", "volatility_60": "lower_is_better"}
+
+        rows = client.get("/api/composites").json()
+        assert len(rows) == 1
+        detail = client.get(f"/api/composites/{cid}").json()
+        assert detail["name"] == "质量动量组合"
+
+        assert client.delete(f"/api/composites/{cid}").status_code == 200
+        assert client.get(f"/api/composites/{cid}").status_code == 404
+        assert client.delete(f"/api/composites/{cid}").status_code == 404
+
+    def test_unknown_factor_rejected(self, client) -> None:
+        resp = client.post(
+            "/api/composites",
+            json={
+                "name": "坏组合",
+                "components": [{"name": "no_such_factor", "weight": 1}],
+            },
+        )
+        assert resp.status_code == 400
+        assert "no_such_factor" in resp.json()["detail"]
+
+    def test_duplicate_name_400(self, client) -> None:
+        body = {"name": "同名", "components": [{"name": "momentum_60", "weight": 1}]}
+        assert client.post("/api/composites", json=body).status_code == 200
+        assert client.post("/api/composites", json=body).status_code == 400