The invention relates to a time-varying deconvolution method based on seismic in-phase axis wavelet spectrum, belonging to the field of seismic exploration. The method specifically comprises the following steps: firstly, using a seismic in-phase axis tracking technology to obtain in-phase axes corresponding to different strata, and then, based on the in-phase axis, realizing extraction of the seismic in-phase axis wavelet spectrum; for each of the in-phase axes in the seismic record, generating a desired wavelet spectrum correction factor by using the desired wavelet spectrum and the wavelet spectrum of the extracted in-phase axis, and combining the desired wavelet spectrum correction factors of different in-phase axes on the same seismic trace to obtain a deconvolution factor of the entire seismic trace, and finally, realizing the deconvolution calculation process based on the deconvolution factor. According to the method of the invention, the seismic in-phase axis wavelet spectrum corresponding to different strata can be well extracted, and targeted deconvolution processing is realized in combination with the characteristics of different strata, so that the seismic recording resolution is higher, the needs for high-resolution seismic exploration can be more adapted to, which lays a good foundation for the subsequent seismic exploration processing and inversion interpretationwork.