A method and a device for tracking background noise in a communication system are provided. The method includes: calculating a SNR of a current frame according to input audio signals; increasing a frame counter, and calculating tone features and signal steadiness features of the current frame if the SNR of the current frame is not less than a first threshold; determining the possibility of a time window including a noise interval according to the calculated tone feature values and signal steadiness feature values of each frame of the time window when the frame counter is increased to the length of the time window; and extracting noise features in the time window. Existence of background noise is analyzed continuously in a time window, so that background noise that changes frequently.