Abstract: Embodiments of the present invention provide a method and device for transcoding, which belongs to the computer media processing field. The method includes: receiving multiple multimedia source files selected by a user and a transcoding target parameter inputted by the user; separating each of the multiple multimedia source files into an audio stream and a video stream; according to the transcoding target parameter, transcoding each audio stream and each video stream obtained from the separation; merging transcoded audio streams and transcoded video streams of the multiple multimedia source files into at least one multimedia target file. The device includes: a receiving unit, a separating unit, a transcoding unit and a merging unit. The present invention extends transcoding modes, improves user experience, and has high practicability.