Abstract: Time frequency analysis is an important and new branch of mathematics that has been developed recently.It has become a very active research field all over the world now.In this paper,first we analyze the frequency dispersion characteristic of Rayleigh wave and the shortcoming of the traditional method of parameter abstracting.Then we process the real data in the method of the time frequency analysis.The processing result notes that the method of time frequency analysis may improve stability and liability of extracting Rayleigh wave velocity.