The invention discloses a method for coding and decoding an audio, which mainly solves the problems that the prior method for coding and decoding the audio has low compression ratio and poor reconstruction audio quality. The method comprises the following steps: adopting a time frequency translation and frequency domain filtering method or a time domain filtering and time frequency translation method to analyze an audio signal so as to obtain a frequency domain residual error signal; dividing the frequency domain residual error signal into a low frequency residual error signal and a high frequency residual error signal, and performing direct coding on the low frequency residual error signal and performing parameter coding on the high frequency residual error signal respectively; reconstructing the high frequency residual error signal through the decoded low frequency residual error signal and the decoded high frequency residual error; recombining the decoded low frequency residual error signal and the reconstructed high frequency residual error signal to obtain a reconstructed frequency domain residual error signal; and finally adopting a frequency domain inverse filtering and time frequency inverse transform method or a time frequency inverse transform and time domain inverse filtering method to obtain a reconstructed audio signal. The method eliminates the redundancy in the frequency domain residual error signal and improves the compression ratio of audio coding, the channel utilization rate and the audio transmission quality, and is applied to multimedia communication and consumer electronics.