The invention discloses a method for adding background sound in a call. The method comprises the following steps: when an incoming call or an outgoing call is motored and when the call is started, sending a request of obtaining audio data constructing ambient sound in the current call to a server; receiving at least one segment of the audio data corresponding to the request fed back by the server; and when a user is detected to trigger a background sound playing button in the call, outputting the at least one segment of the audio data together with MIC sampling voice data as first background sound in the cal to construct the ambient sound. The invention further discloses a terminal and a system. By adoption of the scheme, the ambient sound can be added in the call to simulate virtual scenes.