diff --git a/vnpy/app/algo_trading/algos/stop_algo.py b/vnpy/app/algo_trading/algos/stop_algo.py
index 14b5e94f..a25bc0e9 100644
--- a/vnpy/app/algo_trading/algos/stop_algo.py
+++ b/vnpy/app/algo_trading/algos/stop_algo.py
@@ -85,7 +85,7 @@ class StopAlgo(AlgoTemplate):
                 if tick.limit_down:
                     price = max(price, tick.limit_down)
 
-                self.vt_orderid = self.buy(
+                self.vt_orderid = self.sell(
                     self.vt_symbol,
                     price,
                     self.volume,