The invention discloses an audio and video synchronous playing method based on audio scaling. The whole playing process is processed according to an Audio playing thread and a Video playing thread, the Audio playing thread dominates the time control of the whole playing, the two threads share the same buffer area, the buffer area receives audio and video data transmitted from the upstream, two sample queues arranged according to a timestamp sequence are formed, and the sample at the foremost end of the queues is the sample to be played and processed at present; the method specifically comprises the following steps: after a buffer area is initialized, emptying a queue; setting media playing time mediaPlayTime, namely accumulated audio sample time, setting the media playing time mediaPlayTime by an Audio playing thread, and resetting an initial value; setting an audio scaling time value tDelta to represent the amplitude of the current Audio data needing to be scaled, setting the value bythe Video playing thread, reading the value by the Audio playing thread, and controlling playing according to the value. The invention has the advantages that audio and video playing synchronizationis achieved, the principle is simple, operation is convenient, implementation is easy, and the effect is obvious.