The disclosure relates to a synchronously playing method and device of a media file, and a storage medium, the method includes: creating a media source object corresponding to a playing window in a webpage through a player embedded into the webpage; adding different tracks in the fragmented media file into the same source buffer object in the media source object; transmitting a virtual address taking the media source object as a data source to a media element of the webpage; calling the media element to parse the media source object associated with the virtual address, and reading the tracks in the source buffer object of the associated media source object, and decoding and playing the tracks.