The embodiment of the invention discloses a voice signal processing method, including the steps of: carrying out low-pass filtering processing on a first self-adaptive code vector and obtaining a second self-adaptive code vector; obtaining an energy scaling factor according to a first energy value of the first self-adaptive code vector and a second energy value of the second self-adaptive code vector; adopting the energy scaling factor to carry out energy scaling on the second self-adaptive code vector and obtaining a third self-adaptive code vector; and synthesizing a fixing code vector and the third self-adaptive code vector into a first excitation signal. The embodiment also discloses a voice signal processing device. By the use of the embodiment, a relatively good effect of enhanced fundamental tone is achieved by directly carrying out low-pass filtering on the self-adaptive code vectors, and the subjective hearing effect is improved by using the energy scaling factor to carry outenergy smoothness on the excitation signal obtained by processing.