diff --git a/src/main/java/com/alibaba/dashscope/audio/ttsv2/SpeechSynthesizer.java b/src/main/java/com/alibaba/dashscope/audio/ttsv2/SpeechSynthesizer.java
index 8b382ac..abf90cc 100644
--- a/src/main/java/com/alibaba/dashscope/audio/ttsv2/SpeechSynthesizer.java
+++ b/src/main/java/com/alibaba/dashscope/audio/ttsv2/SpeechSynthesizer.java
@@ -9,6 +9,7 @@
 import com.alibaba.dashscope.exception.InputRequiredException;
 import com.alibaba.dashscope.exception.NoApiKeyException;
 import com.alibaba.dashscope.protocol.*;
+import com.alibaba.dashscope.utils.JsonUtils;
 import com.google.gson.JsonObject;
 import io.reactivex.BackpressureStrategy;
 import io.reactivex.Emitter;
@@ -44,7 +45,7 @@ public final class SpeechSynthesizer {
   SynchronizeFullDuplexApi<SpeechSynthesisParam> duplexApi;
 
   private ApiServiceOption serviceOption;
-  private Emitter<String> textEmitter;
+  private Emitter<TextStreamItem> textEmitter;
   private ResultCallback<SpeechSynthesisResult> callback;
   private SpeechSynthesisState state = SpeechSynthesisState.IDLE;
 
@@ -235,10 +236,11 @@ public Flowable<SpeechSynthesisResult> streamingCallAsFlowable(Flowable<String>
     startStreamTimeStamp = System.currentTimeMillis();
     recvAudioLength = 0;
     preRequestId = UUID.randomUUID().toString();
+    Flowable<TextStreamItem> inputStream = textStream.map(text -> new TextStreamItem(text));
     return duplexApi
         .duplexCall(
             StreamInputTtsParamWithStream.fromStreamInputTtsParam(
-                this.parameters, textStream, preRequestId, false))
+                this.parameters, inputStream, preRequestId, false))
         .filter(item -> item.getEvent() != WebSocketEventType.TASK_STARTED.getValue())
         .map(SpeechSynthesisResult::fromDashScopeResult)
         .filter(item -> !canceled.get())
@@ -284,7 +286,7 @@ public Flowable<SpeechSynthesisResult> callAsFlowable(String text)
                     emitter -> {
                       new Thread(
                               () -> {
-                                emitter.onNext(text);
+                                emitter.onNext(new TextStreamItem(text));
                                 emitter.onComplete();
                               })
                           .start();
@@ -336,7 +338,7 @@ private void startStream(boolean enableSsml) {
     //        timestamps.clear();
     WritableByteChannel channel = Channels.newChannel(outputStream);
 
-    Flowable<String> textFrames =
+    Flowable<TextStreamItem> textFrames =
         Flowable.create(
             emitter -> {
               synchronized (SpeechSynthesizer.this) {
@@ -346,7 +348,7 @@ private void startStream(boolean enableSsml) {
                       emitter.onComplete();
                       return;
                     } else {
-                      emitter.onNext(buffer.text);
+                      emitter.onNext(buffer.item);
                     }
                   }
                   cmdBuffer.clear();
@@ -507,10 +509,10 @@ private void submitText(String text) {
       }
       if (textEmitter == null) {
         log.debug("submitText to new emitter: " + text);
-        cmdBuffer.add(AsyncCmdBuffer.builder().text(text).build());
+        cmdBuffer.add(AsyncCmdBuffer.builder().item(new TextStreamItem(text)).build());
       } else {
         log.debug("submitText to emitter: " + text);
-        textEmitter.onNext(text);
+        textEmitter.onNext(new TextStreamItem(text));
       }
     }
   }
@@ -660,6 +662,40 @@ public void streamingCall(String text) {
     }
   }
 
+  public void streamingFlush() {
+    synchronized (this) {
+      if (state != SpeechSynthesisState.TTS_STARTED) {
+        throw new ApiException(
+            new InputRequiredException(
+                "State invalid: expect stream input tts state is started but " + state.getValue()));
+      }
+      if (textEmitter == null) {
+        log.debug("submitFlush to new emitter");
+        cmdBuffer.add(AsyncCmdBuffer.builder().item(new TextStreamItem(true)).build());
+      } else {
+        log.debug("submitFlush to emitter");
+        textEmitter.onNext(new TextStreamItem(true));
+      }
+    }
+  }
+
+  public void streamingFlush(JsonObject params) {
+    synchronized (this) {
+      if (state != SpeechSynthesisState.TTS_STARTED) {
+        throw new ApiException(
+            new InputRequiredException(
+                "State invalid: expect stream input tts state is started but " + state.getValue()));
+      }
+      if (textEmitter == null) {
+        log.debug("submitFlush to new emitter");
+        cmdBuffer.add(AsyncCmdBuffer.builder().item(new TextStreamItem(true, params)).build());
+      } else {
+        log.debug("submitFlush to emitter");
+        textEmitter.onNext(new TextStreamItem(true, params));
+      }
+    }
+  }
+
   /**
    * Speech synthesis If a callback is set, the audio will be returned in real-time through the
    * on_event interface Otherwise, this function blocks until all audio is received and then returns
@@ -750,17 +786,39 @@ public ByteBuffer call(String text) {
   @SuperBuilder
   private static class AsyncCmdBuffer {
     @Builder.Default private boolean isStop = false;
-    private String text;
+    private TextStreamItem item;
+  }
+
+  private class TextStreamItem {
+    public TextStreamItem(String text) {
+      this.text = text;
+      this.flush = false;
+    }
+
+    public TextStreamItem(boolean flush) {
+      this.text = null;
+      this.flush = flush;
+    }
+
+    public TextStreamItem(boolean flush, JsonObject params) {
+      this.text = null;
+      this.flush = flush;
+      this.params = params;
+    }
+
+    public String text;
+    public boolean flush;
+    public JsonObject params;
   }
 
   @SuperBuilder
   private static class StreamInputTtsParamWithStream extends SpeechSynthesisParam {
 
-    @NonNull private Flowable<String> textStream;
+    @NonNull private Flowable<TextStreamItem> textStream;
 
     public static StreamInputTtsParamWithStream fromStreamInputTtsParam(
         SpeechSynthesisParam param,
-        Flowable<String> textStream,
+        Flowable<TextStreamItem> textStream,
         String preRequestId,
         boolean enableSsml) {
       return StreamInputTtsParamWithStream.builder()
@@ -780,10 +838,24 @@ public static StreamInputTtsParamWithStream fromStreamInputTtsParam(
     public Flowable<Object> getStreamingData() {
       return textStream
           .map(
-              text -> {
-                JsonObject jsonObject = new JsonObject();
-                jsonObject.addProperty("text", text);
-                return jsonObject;
+              item -> {
+                if (!item.flush) {
+                  JsonObject jsonObject = new JsonObject();
+                  jsonObject.addProperty("text", item.text);
+                  return jsonObject;
+                } else {
+                  JsonObject jsonObject = new JsonObject();
+                  jsonObject.addProperty("flush", true);
+                  if (item.params != null && !item.params.isJsonNull()) {
+                    for (String key : item.params.keySet()) {
+                      Object value = item.params.get(key);
+                      if (key != null && value != null) {
+                        jsonObject.add(key, JsonUtils.toJsonElement(value));
+                      }
+                    }
+                  }
+                  return jsonObject;
+                }
               })
           .cast(Object.class);
     }