An echo cancelation method is disclosed. The method includes: dividing a to-be-processed audio signal into a to-be-processed high-band audio signal and a to-be-processed low-band audio signal; performing, by using an AEC module, adaptive filtering echo cancelation processing on the to-be-processed low-band audio signal, and skipping performing adaptive filtering echo cancelation processing on the to-be-processed high-band audio signal, to generate a preliminary echo cancelation signal; performing, by using an RES module, envelope prediction echo suppression on a high-band signal in a preliminary echo cancelation frequency domain signal, and calculating and outputting a residual echo suppression coefficient; performing, by using the RES module, echo suppression on a low-band signal in a preliminary echo cancelation frequency domain signal, and outputting a processing result; and multiplying the output result and the residual echo suppression coefficient, and outputting a signal of which echoes are canceled. In addition, an echo cancelation device is provided. In the embodiments of the present invention, high-band processing and low-band processing are separately performed on a to-be-processed signal, thereby not only effectively reducing a calculation amount of echo cancelation, but also solving a problem of echo leakage existing on sub-band edges in the prior art.