File transmission method and device

The invention relates to a file transmission method and device. The file transmission method is applied to a back end, the back end comprises a plurality of first threads which can be executed in parallel, and the method comprises the steps of obtaining a transmission request of a to-be-transmitted file; if the transmission request is sent by a plurality of second threads which are included in the front end and can be executed in parallel, it is determined that the transmission mode of the file to be transmitted is that the rear end downloads the file from the front end, the transmission request comprises transmission information of a first file block, and the first file block is obtained by the front end through block calculation of the file to be transmitted; the first thread is used for carrying out iterative downloading of the first file block according to the preset block size and the transmission information, and the first file block is sent by the second thread from the front end to the rear end. Accor