A method and a device for processing a sound signal for a communications device, where a relationship between values of a volume of a first sound signal collected by a main microphone and a volume of a second sound signal collected by an auxiliary microphone is acquired by comparison, to determine a sound signal processing policy, and according to the sound signal processing policy, a sound signal to be sent to a peer communications terminal is determined, where the sound signal processing policy is used to ensure that a volume of the sound signal to be sent to the peer communications terminal exceeds a preset volume threshold.