diff --git a/webui/src/components/ParameterForm.vue b/webui/src/components/ParameterForm.vue
index e98b6e7..8a9dadb 100644
--- a/webui/src/components/ParameterForm.vue
+++ b/webui/src/components/ParameterForm.vue
@@ -35,7 +35,7 @@
                   <div class="col-12 col-md-6">
                     <q-input
                       :model-value="currentType"
-                      label="电流类型"
+                      label="电压类型 (AC/DC)"
                       readonly
                     >
                       <q-tooltip>交流(AC)或直流(DC)，由电压等级自动判断</q-tooltip>
@@ -342,7 +342,7 @@
 
             <!-- 运行日志 -->
             <LogComponent ref="logRef" />
-            
+
           </div>
         </q-page>
       </q-page-container>
@@ -377,7 +377,7 @@ const defaultParams: AllParameters = {
   },
   optional: {
     voltage_n: 3,
-    max_i: 200
+    max_i: 300
   }
 }
 
@@ -398,11 +398,14 @@ const currentType = computed(() => {
   return params.parameter.rated_voltage.includes('±') ? 'DC' : 'AC'
 })
 
-// 监听电压等级变化，同步更新 ac_or_dc 字段
+// 监听电压等级变化，同步更新 ac_or_dc 和 voltage_n 字段
 watch(
   () => params.parameter.rated_voltage,
   (newVoltage) => {
-    params.parameter.ac_or_dc = newVoltage.includes('±') ? 'DC' : 'AC'
+    const isDC = newVoltage.includes('±')
+    params.parameter.ac_or_dc = isDC ? 'DC' : 'AC'
+    // DC 时电压份数为 1，AC 时为 3
+    params.optional.voltage_n = isDC ? 1 : 3
   },
   { immediate: true }
 )