diff --git a/lib/options/options_coin_open_lib.py b/lib/options/options_coin_open_lib.py
index a14f310..f9923a9 100644
--- a/lib/options/options_coin_open_lib.py
+++ b/lib/options/options_coin_open_lib.py
@@ -202,6 +202,32 @@ def open_coin_option_buy_full(
             tick_sz=tick_sz,
             ord_type="ioc",
         )
+        # 51008 时自动减半张数再试一次(买币已到位,避免整笔回滚)
+        if (not order.get("ok")) and sheets > 1:
+            msg_l = str(order.get("msg") or "").lower()
+            if "51008" in str(order.get("raw") or "").lower() or "不足" in str(order.get("msg") or ""):
+                sheets2 = max(1, sheets // 2)
+                if sheets2 < sheets:
+                    order2 = cfg["place_option_limit_order"](
+                        ex,
+                        inst_id=inst_id,
+                        side="buy",
+                        sheets=sheets2,
+                        price=float(ask),
+                        td_mode=td_mode_for_option_buy(cfg.get("td_mode")),
+                        tick_sz=tick_sz,
+                        ord_type="ioc",
+                    )
+                    if order2.get("ok"):
+                        order = order2
+                        sheets = sheets2
+                        sizing = {
+                            "ok": True,
+                            "sheets": sheets,
+                            "eth_amount": round(sheets * ct_mult, 8),
+                            "coin_premium": round(sheets * float(ask) * ct_mult, 8),
+                            "retried_half": True,
+                        }
         if not order.get("ok"):
             rb = rollback_bought_coin_to_usdt(
                 conn, ex, bridge_id=bridge_id, underlying=underlying, reason=order.get("msg") or "下单失败"