An earphone signal processing method, characterized in that the method comprises: acquiring a signal picked up by a first microphone of an earphone at a position close to a mouth outside an ear canal, a signal picked up by a second microphone of the earphone (S 102) at a position away from the mouth outside the ear canal and a signal picked up by a third microphone of the earphone, the third microphone being in a cavity formed by the earphone and the ear canal; performing dual-microphone noise reduction on the signal picked up by the first microphone and the signal picked up by the second microphone to obtain a first intermediate signal, and performing dual-microphone noise reduction on the signal picked up by the second microphone and the signal picked up by the third microphone to obtain a second intermediate signal; fusing (S 140) the first intermediate signal and the second intermediate signal to obtain a fused voice signal; and outputting (S 150) the fused voice signal; wherein the fused voice signal comprises a low-frequency part of the second intermediate signal and a medium-high frequency part of the first intermediate signal; wherein fusing the first intermediate signal and the second intermediate signal to obtain the fused voice signal comprises: correspondingly dividing the first intermediate signal and the second intermediate signal to multiple sub bands, performing weighted fusion on the first intermediate signal and the second intermediate signal in each sub band according to different weights, and combining weighted results of each sub band to obtain the fused voice signal; wherein the weights for the weighted fusion are adaptively adjusted according to acoustic environment, wherein the weight of the first intermediate signal during the low-frequency fusion is increased in response to a sound pressure level being low, and the weight of the second intermediate signal during the low-frequency fusion is increased in response to the sound pressure level being high. acquiring a signal picked up by a first microphone of an earphone at a position close to a mouth outside an ear canal, a signal picked up by a second microphone of the earphone (S 102) at a position away from the mouth outside the ear canal and a signal picked up by a third microphone of the earphone, the third microphone being in a cavity formed by the earphone and the ear canal; performing dual-microphone noise reduction on the signal picked up by the first microphone and the signal picked up by the second microphone to obtain a first intermediate signal, and performing dual-microphone noise reduction on the signal picked up by the second microphone and the signal picked up by the third microphone to obtain a second intermediate signal; fusing (S 140) the first intermediate signal and the second intermediate signal to obtain a fused voice signal; and outputting (S 150) the fused voice signal; wherein the fused voice signal comprises a low-frequency part of the second intermediate signal and a medium-high frequency part of the first intermediate signal; wherein fusing the first intermediate signal and the second intermediate signal to obtain the fused voice signal comprises: correspondingly dividing the first intermediate signal and the second intermediate signal to multiple sub bands, performing weighted fusion on the first intermediate signal and the second intermediate signal in each sub band according to different weights, and combining weighted results of each sub band to obtain the fused voice signal; wherein the weights for the weighted fusion are adaptively adjusted according to acoustic environment, wherein the weight of the first intermediate signal during the low-frequency fusion is increased in response to a sound pressure level being low, and the weight of the second intermediate signal during the low-frequency fusion is increased in response to the sound pressure level being high.