diff --git a/apps/vendor-okx/src/index.ts b/apps/vendor-okx/src/index.ts
index d32035697..cf3f651b3 100644
--- a/apps/vendor-okx/src/index.ts
+++ b/apps/vendor-okx/src/index.ts
@@ -348,7 +348,10 @@ const tradingAccountInfo$ = combineLatest([
       const usdtBalance = balanceApi.data[0]?.details.find((x) => x.ccy === 'USDT');
       const equity = +(usdtBalance?.eq ?? 0);
       const balance = +(usdtBalance?.cashBal ?? 0);
-      const free = +(usdtBalance?.availEq ?? 0);
+      const free = Math.min(
+        balance, // free should no more than balance if there is much profits
+        +(usdtBalance?.availEq ?? 0),
+      );
       const used = equity - free;
       // const used = +usdtBalance.frozenBal;
       const profit = equity - balance;
diff --git a/common/changes/@yuants/vendor-okx/2024-11-09-23-28.json b/common/changes/@yuants/vendor-okx/2024-11-09-23-28.json
new file mode 100644
index 000000000..1151a9507
--- /dev/null
+++ b/common/changes/@yuants/vendor-okx/2024-11-09-23-28.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@yuants/vendor-okx",
+      "comment": "fix free margin calculations of trading account",
+      "type": "patch"
+    }
+  ],
+  "packageName": "@yuants/vendor-okx"
+}
\ No newline at end of file