The present invention relates to a method and device for dereverberation of single-channel speech. The method includes the following steps of framing an input single channel speech signal, and processing the frame signals as follows according to a time sequence: performing short-time Fourier transform on a current frame to obtain a power spectrum and a phase spectrum of the current frame; selecting several frames previous to the current frame and having a distance from the current frame within a set duration range, and performing linear superposition on the power spectra of these frames to estimate the power spectrum of a late reflection sound of the current frame; removing the estimated power spectrum of the late reflection sound of the current frame from the power spectrum of the current frame by a spectral subtraction method to obtain the power spectra of a direct sound and an early reflection sound of the current frame; and performing inverse short-time Fourier transform on the power spectra of the direct sound and the early reflection sound of the current frame and the phase spectrum of the current frame together to obtain a signal of the current frame after dereverberation. The dereverberation method and device can solve the problem that the estimation of a transfer function of a reverberation environment or the estimation of reverberation time is difficult in the dereverberation of single-channel speech.