diff --git a/sanguo_trader/matcher.py b/sanguo_trader/matcher.py
index 3f19e8f..7640776 100644
--- a/sanguo_trader/matcher.py
+++ b/sanguo_trader/matcher.py
@@ -72,6 +72,10 @@ def cross_order(
         fill_price = float(match_bar["open"])
     elif order.match_session == MatchSession.CURRENT_CLOSE:
         fill_price = float(match_bar["close"])
+    elif order.match_session == MatchSession.CALL_AUCTION:
+        # 集合竞价开盘价（最大成交量原则 → open）。当前同 NEXT_OPEN 定价；
+        # 未来区分开盘/尾盘集合竞价需扩枚举（CALL_AUCTION_OPEN/CLOSE）。
+        fill_price = float(match_bar["open"])
     else:
         return PaperReject(
             order.strategy_id, symbol, "unsupported_match_session", bar_date
diff --git a/tests/trader/test_matcher.py b/tests/trader/test_matcher.py
index cd6d019..4a115c7 100644
--- a/tests/trader/test_matcher.py
+++ b/tests/trader/test_matcher.py
@@ -110,11 +110,12 @@ def test_st_5pct_limit_up():
     assert isinstance(r, PaperReject) and r.reason == "limit_up_locked"
 
 
-def test_call_auction_session_rejected():
-    """CALL_AUCTION 首版预留，不支持。"""
+def test_call_auction_fills_at_open():
+    """集合竞价撮合用开盘价（最大成交量原则 → open，分期项）。"""
     o = buy(market=True, session=MatchSession.CALL_AUCTION)
-    r = cross_order(o, mkbar(10.5, 11, 10.2, 10.8), PREV, CFG)
-    assert isinstance(r, PaperReject) and r.reason == "unsupported_match_session"
+    t = cross_order(o, mkbar(10.5, 11, 10.2, 10.8), PREV, CFG)
+    assert isinstance(t, PaperTrade)
+    assert t.price == 10.5   # 集合竞价开盘价 = open
 
 
 # ---- 限价单触价 ----