diff --git a/app/repositories/ad_feed_reward.py b/app/repositories/ad_feed_reward.py
index a90c0c7..1649b89 100644
--- a/app/repositories/ad_feed_reward.py
+++ b/app/repositories/ad_feed_reward.py
@@ -219,7 +219,7 @@ def grant_feed_reward(
     crud_wallet.grant_coins(
         db, user_id, coin,
         biz_type=reward_biz, ref_id=client_event_id,
-        remark=reward_remark,
+        remark=reward_remark, trace_id=trace_id,
     )
     rec = AdFeedRewardRecord(
         client_event_id=client_event_id,
diff --git a/tests/test_welfare.py b/tests/test_welfare.py
index 72b0ff0..a7d6abe 100644
--- a/tests/test_welfare.py
+++ b/tests/test_welfare.py
@@ -6,7 +6,7 @@ from __future__ import annotations
 
 import json
 
-from sqlalchemy import text
+from sqlalchemy import select, text
 
 from app.core.config import settings
 from app.core.rewards import (
@@ -20,6 +20,8 @@ from app.core.rewards import (
 from app.db.session import SessionLocal
 from app.integrations import pangle
 from app.models.ad_feed_reward import AdFeedRewardRecord
+from app.models.wallet import CoinTransaction
+from app.repositories import ad_feed_reward as crud_feed
 from app.repositories import wallet as crud_wallet
 from app.repositories.user import get_user_by_phone
 
@@ -461,3 +463,26 @@ def test_backfill_coin_trace_id_from_ad_record(client) -> None:
         assert c2.trace_id == "trace-CPN"
         assert c3.trace_id is None          # 无关类型不动
         assert c4.trace_id is None          # 广告行 trace_id 为空 → EXISTS 守护跳过、保持 NULL
+
+
+def test_grant_feed_reward_sets_coin_trace_id(client) -> None:
+    """grant_feed_reward(comparison) 把 trace_id 透传给 grant_coins,coin_transaction 带上本场 trace_id。"""
+    phone = "13800002003"
+    _login(client, phone)
+    with SessionLocal() as db:
+        user = get_user_by_phone(db, phone)
+        assert user is not None
+        rec = crud_feed.grant_feed_reward(
+            db, user.id,
+            client_event_id="evt-fr-1", ecpm="1000", duration_seconds=10,
+            feed_scene="comparison", trace_id="trace-FR", display_coin=5,
+        )
+        assert rec.status == "granted", rec.status
+        txn = db.execute(
+            select(CoinTransaction).where(
+                CoinTransaction.user_id == user.id,
+                CoinTransaction.ref_id == "evt-fr-1",
+            )
+        ).scalar_one()
+        assert txn.biz_type == "feed_ad_reward_comparison"
+        assert txn.trace_id == "trace-FR"