A method and apparatus for generating an excitation signal for background noise are provided. The method includes: generating a quasi excitation signal by utilizing coding parameters in a speech coding/decoding stage and a transition length of an excitation signal; and obtaining the excitation signal for background noise in a transition stage by generating a weighted sum of the quasi excitation signal and a random excitation signal of a background noise frame. Moreover, the apparatus includes: a quasi excitation signal generation unit and a transition stage excitation signal acquisition unit. Through the synthesizing scheme of comfortable background noise according to the present invention, the transition of a synthesized signal from speech to background noise could be more natural, smooth and continuous, which makes the listeners feel more comfortable.