The invention provides a single-channel speech enhancement method. The method is realized through a speech enhancement network model. The speech enhancement network model comprises an analysis layer,an encoder, a time convolution module, a decoder and a synthesis layer. According to the single-channel speech enhancement method provided by the invention, an analysis layer of quasi-short-time windowed Fourier transform based on convolution layer design and a synthesis layer of quasi-inverse short-time windowed Fourier transform are added, so that the characteristics of speech are better mined in a transform domain. Besides, the encoder and the decoder are constructed by adopting the gating convolution layer so as to expand the receptive field, transmission of information in the hierarchicalstructure can be better controlled, and the time convolution module is added between the encoder and the decoder so as to better learn the long-term memory characteristic of the speech, so that the speech enhancement effect can be enhanced. Meanwhile, the invention provides a single-channel speech enhancement system and a speech enhancement network model.