diff --git a/vnpy/trader/app/spreadTrading/stAlgo.py b/vnpy/trader/app/spreadTrading/stAlgo.py
index 2a5444d3..76a895c8 100644
--- a/vnpy/trader/app/spreadTrading/stAlgo.py
+++ b/vnpy/trader/app/spreadTrading/stAlgo.py
@@ -288,6 +288,33 @@ class SniperAlgo(StAlgoTemplate):
         if self.hedgeCount > self.hedgeInterval:
             self.cancelAllPassiveLegOrders()
             self.hedgeCount = 0
+    
+    #----------------------------------------------------------------------
+    def checkPrice(self):
+        """检查价格"""
+        # 做多检查
+        if self.mode != self.MODE_SHORTONLY:
+            if self.buyPrice >= self.sellPrice:
+                self.writeLog(u'启动失败，允许多头交易时BuyPrice必须小于SellPrice')
+                return False
+            
+        # 做空检查
+        if self.mode != self.MODE_LONGONLY:
+            if self.shortPrice <= self.coverPrice:
+                self.writeLog(u'启动失败，允许空头交易时ShortPrice必须大于CoverPrice')
+                return False
+            
+        # 多空检查
+        if self.mode == self.MODE_LONGSHORT:
+            if self.buyPrice >= self.coverPrice:
+                self.writeLog(u'启动失败，允许双向交易时BuyPrice必须小于CoverPrice')
+                return False
+            
+            if self.shortPrice <= self.sellPrice:
+                self.writeLog(u'启动失败，允许双向交易时ShortPrice必须大于SellPrice')
+                return False
+            
+        return True
         
     #----------------------------------------------------------------------
     def start(self):
@@ -296,27 +323,9 @@ class SniperAlgo(StAlgoTemplate):
         if self.active:
             return self.active
         
-        # 做多检查
-        if self.mode != self.MODE_SHORTONLY:
-            if self.buyPrice >= self.sellPrice:
-                self.writeLog(u'启动失败，允许多头交易时BuyPrice必须小于SellPrice')
-                return self.active
-            
-        # 做空检查
-        if self.mode != self.MODE_LONGONLY:
-            if self.shortPrice <= self.coverPrice:
-                self.writeLog(u'启动失败，允许空头交易时ShortPrice必须大于CoverPrice')
-                return self.active
-            
-        # 多空检查
-        if self.mode == self.MODE_LONGSHORT:
-            if self.buyPrice >= self.coverPrice:
-                self.writeLog(u'启动失败，允许双向交易时BuyPrice必须小于CoverPrice')
-                return self.active
-            
-            if self.shortPrice <= self.sellPrice:
-                self.writeLog(u'启动失败，允许双向交易时ShortPrice必须大于SellPrice')
-                return self.active
+        # 检查价格安全性
+        if not self.checkPrice():
+            return False
         
         # 启动算法
         self.quoteCount = 0
diff --git a/vnpy/trader/app/spreadTrading/uiStWidget.py b/vnpy/trader/app/spreadTrading/uiStWidget.py
index 0445a24b..a6881378 100644
--- a/vnpy/trader/app/spreadTrading/uiStWidget.py
+++ b/vnpy/trader/app/spreadTrading/uiStWidget.py
@@ -141,7 +141,16 @@ class StBuyPriceSpinBox(QtWidgets.QDoubleSpinBox):
     def setPrice(self, value):
         """设置价格"""
         self.algoEngine.setAlgoBuyPrice(self.spreadName, value)
-    
+   
+    #----------------------------------------------------------------------
+    def algoActiveChanged(self, active):
+        """算法运行状态改变"""
+        # 只允许算法停止时修改运行模式
+        if active:
+            self.setEnabled(False)
+        else:
+            self.setEnabled(True)    
+
 
 ########################################################################
 class StSellPriceSpinBox(QtWidgets.QDoubleSpinBox):
@@ -165,6 +174,15 @@ class StSellPriceSpinBox(QtWidgets.QDoubleSpinBox):
     def setPrice(self, value):
         """设置价格"""
         self.algoEngine.setAlgoSellPrice(self.spreadName, value)
+    
+    #----------------------------------------------------------------------
+    def algoActiveChanged(self, active):
+        """算法运行状态改变"""
+        # 只允许算法停止时修改运行模式
+        if active:
+            self.setEnabled(False)
+        else:
+            self.setEnabled(True)
 
 
 ########################################################################
@@ -190,6 +208,15 @@ class StShortPriceSpinBox(QtWidgets.QDoubleSpinBox):
         """设置价格"""
         self.algoEngine.setAlgoShortPrice(self.spreadName, value)
 
+    #----------------------------------------------------------------------
+    def algoActiveChanged(self, active):
+        """算法运行状态改变"""
+        # 只允许算法停止时修改运行模式
+        if active:
+            self.setEnabled(False)
+        else:
+            self.setEnabled(True)
+
 
 ########################################################################
 class StCoverPriceSpinBox(QtWidgets.QDoubleSpinBox):
@@ -214,6 +241,15 @@ class StCoverPriceSpinBox(QtWidgets.QDoubleSpinBox):
         """设置价格"""
         self.algoEngine.setAlgoCoverPrice(self.spreadName, value)
     
+    #----------------------------------------------------------------------
+    def algoActiveChanged(self, active):
+        """算法运行状态改变"""
+        # 只允许算法停止时修改运行模式
+        if active:
+            self.setEnabled(False)
+        else:
+            self.setEnabled(True)    
+
 
 ########################################################################
 class StMaxPosSizeSpinBox(QtWidgets.QSpinBox):
@@ -237,7 +273,16 @@ class StMaxPosSizeSpinBox(QtWidgets.QSpinBox):
         """设置价格"""
         self.algoEngine.setAlgoMaxPosSize(self.spreadName, size)
 
-
+    #----------------------------------------------------------------------
+    def algoActiveChanged(self, active):
+        """算法运行状态改变"""
+        # 只允许算法停止时修改运行模式
+        if active:
+            self.setEnabled(False)
+        else:
+            self.setEnabled(True)
+            
+            
 ########################################################################
 class StMaxOrderSizeSpinBox(QtWidgets.QSpinBox):
     """"""
@@ -260,6 +305,15 @@ class StMaxOrderSizeSpinBox(QtWidgets.QSpinBox):
         """设置价格"""
         self.algoEngine.setAlgoMaxOrderSize(self.spreadName, size)    
 
+    #----------------------------------------------------------------------
+    def algoActiveChanged(self, active):
+        """算法运行状态改变"""
+        # 只允许算法停止时修改运行模式
+        if active:
+            self.setEnabled(False)
+        else:
+            self.setEnabled(True)
+
 
 ########################################################################
 class StModeComboBox(QtWidgets.QComboBox):
@@ -422,6 +476,12 @@ class StAlgoManager(QtWidgets.QTableWidget):
             self.setCellWidget(row, 8, comboMode)
             self.setCellWidget(row, 9, buttonActive)
             
+            buttonActive.signalActive.connect(spinBuyPrice.algoActiveChanged)
+            buttonActive.signalActive.connect(spinSellPrice.algoActiveChanged)
+            buttonActive.signalActive.connect(spinShortPrice.algoActiveChanged)
+            buttonActive.signalActive.connect(spinCoverPrice.algoActiveChanged)
+            buttonActive.signalActive.connect(spinMaxOrderSize.algoActiveChanged)
+            buttonActive.signalActive.connect(spinMaxPosSize.algoActiveChanged)
             buttonActive.signalActive.connect(comboMode.algoActiveChanged)
             
             self.buttonActiveDict[d['spreadName']] = buttonActive