The invention provides a transmission method and device of audio and video information and belongs to the technical field of communication. The method comprises the steps of: obtaining first playing content of multimedia information, wherein the first playing content is sent to at least one client; analyzing whether the first playing content accords with a triggering condition of a preset start authority; and if yes, starting the preset audio and video information sending authority of the client. According to the embodiments, the timing for audio and video information sending of the client is automatically determined according to the playing content of the multimedia information, the plurality of clients are prevented from disturbing the playing effect of the multimedia information while simultaneously sending the audio and video information to a server.