A method for recovering lost frame in a media bitstream is provided. When a frame loss event occurs, a decoder obtains a synthesized high frequency band signal of a current lost frame, and recovery information related to the current lost frame. The decoder determines a global gain gradient of the current lost frame, and further determines a global gain of the current lost frame according to the global gain gradient and a global gain of each frame in previous M frames of the current lost frame. A high frequency band signal of the current lost frame is obtained by adjusting the synthesized high frequency band signal of the current lost frame according to the global gain and a subframe gain of the current lost frame. The process enables natural and smooth transitions of the high frequency band signal between the frames, and attenuates noises in the high frequency band signal.