With the development of Internet and HTML5 technology, the application of file upload on the Web is more and more popular. At the same time, the requirement of efficiency, stability, security and universality of file upload, especially large file upload, is higher and higher. However, most of the current file upload methods can not meet these requirements very well. Therefore, this study proposes to use file fragmentation and multi-concurrent transmission method to improve the efficiency of large file transmission, so as to solve the related problems of multi-concurrent transmission control in the front end of the Web and repeated upload of the same file.