Media file transmission method and server

The embodiment of the invention relates to the field of media communication, in particular to a media file transmission method and a server, and aims to solve the problem of network lag when a clientuses a media file in a poor network in the prior art. In the embodiment of the invention, a server acquires a media file transmission request sent by a client; the media file transmission request comprises a media file identifier to be transmitted; the server determines the code rate of the stored media file corresponding to the media file identifier; the server determines a current network bandwidth with the client; when the server determines that the code rates of the stored media files are all greater than the current network bandwidth, code rate adjustment is performed on at least one of the stored media files to obtain a newly added media file; the code rate of the newly added media file is not greater than the current network bandwidth; and the server sends the newly added media fileto the client. Due to the