diff --git a/backend/app/api/v1/endpoints/products.py b/backend/app/api/v1/endpoints/products.py
index 18dfe98..86da566 100644
--- a/backend/app/api/v1/endpoints/products.py
+++ b/backend/app/api/v1/endpoints/products.py
@@ -3,9 +3,11 @@ from __future__ import annotations
 from fastapi import APIRouter, Depends, Query
 from fastapi.responses import Response
 from pydantic import BaseModel, Field
+from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.core.database import get_db
+from app.models.message import ProductMessage
 from app.schemas.product import (
     ProductCreate,
     ProductUpdate,
@@ -136,3 +138,51 @@ async def update_product_overall_status(
     合法值: 备货 | 生产 | 测试 | 维修 | 在库
     """
     return await product_service.update_overall_status(db, serial_number, data.status)
+
+
+# ============================================================
+# 协同留言板
+# ============================================================
+
+class MessageCreate(BaseModel):
+    operator_id: str = Field(..., min_length=1, max_length=50, description="留言人姓名或工号")
+    content: str = Field(..., min_length=1, description="留言内容")
+
+
+@router.get("/{product_id}/messages")
+async def get_product_messages(
+    product_id: str,
+    db: AsyncSession = Depends(get_db),
+):
+    """获取某产品的所有留言（按时间正序）"""
+    result = await db.execute(
+        select(ProductMessage)
+        .where(ProductMessage.product_id == product_id)
+        .order_by(ProductMessage.created_at.asc())
+    )
+    return result.scalars().all()
+
+
+@router.post("/{product_id}/messages", status_code=201)
+async def create_product_message(
+    product_id: str,
+    request: MessageCreate,
+    db: AsyncSession = Depends(get_db),
+    current_user: dict = Depends(get_current_user),
+):
+    """发布新留言（operator_id 由后端 Token 强制覆写，防止越权伪造）"""
+    import uuid
+    real_operator_id = (
+        current_user.get("username")
+        or current_user.get("sub")
+        or request.operator_id
+    )
+    msg = ProductMessage(
+        product_id=uuid.UUID(product_id),
+        operator_id=real_operator_id,
+        content=request.content,
+    )
+    db.add(msg)
+    await db.commit()
+    await db.refresh(msg)
+    return msg