diff --git a/app/src/main/java/com/k2fsa/sherpa/onnx/MainActivity.kt b/app/src/main/java/com/k2fsa/sherpa/onnx/MainActivity.kt
index 8ee8d51..6eed6ad 100644
--- a/app/src/main/java/com/k2fsa/sherpa/onnx/MainActivity.kt
+++ b/app/src/main/java/com/k2fsa/sherpa/onnx/MainActivity.kt
@@ -189,6 +189,10 @@ class MainActivity : AppCompatActivity() {
     // 实测(2026-09-14):2s 短窗 + base 模型下同人 simA 在 0.05~0.7 震荡,
     // 阈值维度已不可分 → 判定窗加长到 4s 拉开分布,阈值回调到 0.35
     private val speakerSwitchDrop = 0.35f   // cos(window, reference) below this => switch
+    // 深低分一票强切(2026-09-16):同人波动实测最低 ~0.39,异人插话窗稳落
+    // 0.14~0.19,0.22 取安全带中枢——深低首票即切(无缝插话 4~6s→3~4s);
+    // 0.22~0.35 浅低维持连续两票,毛刺照旧被误断防护拦下
+    private val deepLowSwitch = 0.22f
     // 最近邻兜底(P1 收紧,2026-09-11):精确匹配不中→top≥0.42 且领先第二名
     // ≥0.06 才归入最相似身份;模糊判新人(修"错并到别人行")
     private val verdictFallbackMin = 0.42f
@@ -771,16 +775,35 @@ class MainActivity : AppCompatActivity() {
                                                     // 路线A:只"预备",不立即切
                                                     switchSuspicionAtMs =
                                                             SystemClock.elapsedRealtime()
+                                                    val deepLow = simA < deepLowSwitch
                                                     Log.i(TAG, "SWITCH-SUSPECT" +
-                                                            " armed fast-endpoint owner=sid$owner")
-                                                    // 无缝插话确证:连续低分够了
-                                                    // → 不等停顿,本窗立即强判
-                                                    if (rollingLowStreak >= forceSwitchStreaks) {
-                                                        pendingForceEndpoint = true
+                                                            " armed fast-endpoint owner=sid$owner" +
+                                                            (if (deepLow) " deepLow" else ""))
+                                                    // 无缝插话确证:深低一票即切;
+                                                    // 浅低维持连续两票。切行同时把
+                                                    // 新说话人挂名(切行即挂名,复用
+                                                    // 开口即查的落地通道 onOnsetSwitch)
+                                                    if (deepLow ||
+                                                        rollingLowStreak >= forceSwitchStreaks
+                                                    ) {
                                                         rollingLowStreak = 0
+                                                        val label = newLabel
+                                                            ?: SpeakerRecognition.nextAutoLabel()
+                                                                .also {
+                                                                    SpeakerRecognition
+                                                                        .fastRegistry
+                                                                        .addAuto(it, emb)
+                                                                }
                                                         Log.i(TAG, "SWITCH-FORCE" +
-                                                                " streak>=$forceSwitchStreaks" +
+                                                                (if (deepLow)
+                                                                    " deep-low<${deepLowSwitch}"
+                                                                else
+                                                                    " streak>=$forceSwitchStreaks") +
+                                                                " label=$label" +
                                                                 " owner=sid$owner")
+                                                        uiHandler.post {
+                                                            onOnsetSwitch(label)
+                                                        }
                                                     }
                                                 }
                                             }