The embodiment of the invention discloses a voice signal restoration method, which comprises the following steps of: splitting a voice frame adjacent to a lost voice frame in a time domain range to generate a plurality of voice segments; introducing a coefficient for the voice segments respectively; multiplying each voice segment introduced with the coefficient by a Hanning window with the same length as the voice segment respectively to obtain a final voice segment; and superposing the final voice segments to cover an area where the lost voice frame is positioned. Meanwhile, the embodiment of the invention also discloses a voice signal restoration device. Through the method and the device, when a voice stretching method is adopted for voice restoration, the superposed waveforms can restore the amplitude of the original voice signal to a greater degree, and the amplitude of the newly generated voice signal is prevented from having too large difference from the original voice signal, so the voice quality is improved.