diff --git a/frontend/src/utils/file.util.ts b/frontend/src/utils/file.util.ts
index 883f3f7..03ed5a2 100644
--- a/frontend/src/utils/file.util.ts
+++ b/frontend/src/utils/file.util.ts
@@ -417,6 +417,63 @@ export interface StreamUploadResult {
   skippedEmptyCount: number;
 }
 
+async function processFileLines(
+  file: File,
+  chunkSize: number,
+  signal: AbortSignal | undefined,
+  onLine?: (line: string, index: number) => Promise<void> | void,
+  onProgress?: (currentBytes: number, totalBytes: number, processedLines: number) => void
+): Promise<{ lineCount: number; skippedEmptyCount: number }> {
+  const fileSize = file.size;
+  let offset = 0;
+  let buffer = "";
+  let skippedEmptyCount = 0;
+  let lineIndex = 0;
+
+  while (offset < fileSize) {
+    if (signal?.aborted) {
+      throw new Error("Upload cancelled");
+    }
+
+    const end = Math.min(offset + chunkSize, fileSize);
+    const chunk = file.slice(offset, end);
+    const text = await readFileAsText(chunk);
+    const combined = buffer + text;
+    const lines = combined.split(/\r?\n/);
+    buffer = lines.pop() || "";
+
+    for (const line of lines) {
+      if (signal?.aborted) {
+        throw new Error("Upload cancelled");
+      }
+      if (!line.trim()) {
+        skippedEmptyCount++;
+        continue;
+      }
+      const currentIndex = lineIndex;
+      lineIndex += 1;
+      if (onLine) {
+        await onLine(line, currentIndex);
+      }
+    }
+
+    offset = end;
+    onProgress?.(offset, fileSize, lineIndex);
+  }
+
+  if (buffer.trim()) {
+    const currentIndex = lineIndex;
+    lineIndex += 1;
+    if (onLine) {
+      await onLine(buffer, currentIndex);
+    }
+  } else if (buffer.length > 0) {
+    skippedEmptyCount++;
+  }
+
+  return { lineCount: lineIndex, skippedEmptyCount };
+}
+
 export async function streamSplitAndUpload(
   file: File,
   uploadFn: (formData: FormData, config?: { onUploadProgress?: (e: { loaded: number; total: number }) => void }) => Promise<unknown>,
@@ -435,83 +492,30 @@ export async function streamSplitAndUpload(
   } = options;
 
   const fileSize = file.size;
-  let offset = 0;
-  let buffer = "";
   let uploadedCount = 0;
   let skippedEmptyCount = 0;
-  let currentBytes = 0;
   
   // 获取文件名基础部分和扩展名
   const originalFileName = fileNamePrefix || file.name;
   const lastDotIndex = originalFileName.lastIndexOf(".");
   const baseName = lastDotIndex > 0 ? originalFileName.slice(0, lastDotIndex) : originalFileName;
   const fileExtension = lastDotIndex > 0 ? originalFileName.slice(lastDotIndex) : "";
-  
-  // 收集所有需要上传的行
-  const pendingLines: { line: string; index: number }[] = [];
-  let lineIndex = 0;
-
-  // 逐块读取文件并收集非空行
-  while (offset < fileSize) {
-    // 检查是否已取消
-    if (signal?.aborted) {
-      throw new Error("Upload cancelled");
-    }
-
-    const end = Math.min(offset + chunkSize, fileSize);
-    const chunk = file.slice(offset, end);
-    const text = await readFileAsText(chunk);
-    
-    // 将新读取的内容追加到 buffer
-    const combined = buffer + text;
-    
-    // 按换行符分割（支持 \n 和 \r\n）
-    const lines = combined.split(/\r?\n/);
-    
-    // 保留最后一行（可能不完整）
-    buffer = lines.pop() || "";
-    
-    // 收集完整行（跳过空行）
-    for (const line of lines) {
-      if (signal?.aborted) {
-        throw new Error("Upload cancelled");
-      }
-      if (!line.trim()) {
-        skippedEmptyCount++;
-        continue;
-      }
-      pendingLines.push({ line, index: lineIndex++ });
-    }
-    
-    currentBytes = end;
-    offset = end;
-    
-    // 每处理完一个 chunk，更新进度
-    onProgress?.(currentBytes, fileSize, uploadedCount);
-  }
-
-  // 处理最后剩余的 buffer（如果文件不以换行符结尾）
-  if (buffer.trim()) {
-    pendingLines.push({ line: buffer, index: lineIndex++ });
-  } else if (buffer.length > 0) {
-    skippedEmptyCount++;
-  }
-
-  const totalFileNum = pendingLines.length;
-  if (totalFileNum === 0) {
-    return {
-      uploadedCount: 0,
-      totalBytes: fileSize,
-      skippedEmptyCount,
-    };
-  }
-
-  if (signal?.aborted) {
-    throw new Error("Upload cancelled");
-  }
 
   let resolvedReqId = initialReqId;
   if (!resolvedReqId) {
+    const scanResult = await processFileLines(file, chunkSize, signal);
+    const totalFileNum = scanResult.lineCount;
+    skippedEmptyCount = scanResult.skippedEmptyCount;
+    if (totalFileNum === 0) {
+      return {
+        uploadedCount: 0,
+        totalBytes: fileSize,
+        skippedEmptyCount,
+      };
+    }
+    if (signal?.aborted) {
+      throw new Error("Upload cancelled");
+    }
     if (!resolveReqId) {
       throw new Error("Missing pre-upload request id");
     }
@@ -521,6 +525,9 @@ export async function streamSplitAndUpload(
     }
     onReqIdResolved?.(resolvedReqId);
   }
+  if (!resolvedReqId) {
+    throw new Error("Missing pre-upload request id");
+  }
 
   /**
    * 上传单行内容
@@ -573,55 +580,65 @@ export async function streamSplitAndUpload(
     });
   }
 
-  /**
-   * 带并发控制的上传队列执行器
-   * 使用任务队列模式，确保不会同时启动所有上传任务
-   */
-  async function executeUploadsWithConcurrency(): Promise<void> {
-    const lines = [...pendingLines];
-    let currentIndex = 0;
-    let activeCount = 0;
-    let resolvedCount = 0;
-    
-    return new Promise((resolve, reject) => {
-      function tryStartNext() {
-        // 检查是否已完成
-        if (resolvedCount >= lines.length) {
-          if (activeCount === 0) {
-            resolve();
-          }
-          return;
-        }
-        
-        // 启动新的上传任务，直到达到最大并发数
-        while (activeCount < maxConcurrency && currentIndex < lines.length) {
-          const { line, index } = lines[currentIndex++];
-          activeCount++;
-          
-          uploadLine(line, index)
-            .then(() => {
-              uploadedCount++;
-              onProgress?.(fileSize, fileSize, uploadedCount);
-            })
-            .catch((err) => {
-              reject(err);
-            })
-            .finally(() => {
-              activeCount--;
-              resolvedCount++;
-              // 尝试启动下一个任务
-              tryStartNext();
-            });
-        }
+  const inFlight = new Set<Promise<void>>();
+  let uploadError: unknown = null;
+  const enqueueUpload = async (line: string, index: number) => {
+    if (signal?.aborted) {
+      throw new Error("Upload cancelled");
+    }
+    if (uploadError) {
+      throw uploadError;
+    }
+    const uploadPromise = uploadLine(line, index)
+      .then(() => {
+        uploadedCount++;
+      })
+      .catch((err) => {
+        uploadError = err;
+      });
+    inFlight.add(uploadPromise);
+    uploadPromise.finally(() => inFlight.delete(uploadPromise));
+    if (inFlight.size >= maxConcurrency) {
+      await Promise.race(inFlight);
+      if (uploadError) {
+        throw uploadError;
       }
-      
-      // 开始执行
-      tryStartNext();
-    });
+    }
+  };
+
+  let uploadResult: { lineCount: number; skippedEmptyCount: number } | null = null;
+  try {
+    uploadResult = await processFileLines(
+      file,
+      chunkSize,
+      signal,
+      enqueueUpload,
+      (currentBytes, totalBytes) => {
+        onProgress?.(currentBytes, totalBytes, uploadedCount);
+      }
+    );
+    if (uploadError) {
+      throw uploadError;
+    }
+  } finally {
+    if (inFlight.size > 0) {
+      await Promise.allSettled(inFlight);
+    }
   }
 
-  // 使用并发控制执行所有上传
-  await executeUploadsWithConcurrency();
+  if (!uploadResult || (initialReqId && uploadResult.lineCount === 0)) {
+    return {
+      uploadedCount: 0,
+      totalBytes: fileSize,
+      skippedEmptyCount: uploadResult?.skippedEmptyCount ?? 0,
+    };
+  }
+
+  if (!initialReqId) {
+    skippedEmptyCount = skippedEmptyCount || uploadResult.skippedEmptyCount;
+  } else {
+    skippedEmptyCount = uploadResult.skippedEmptyCount;
+  }
 
   return {
     uploadedCount,