Pre-stack velocity is an important link of seismic data processing and an important attribute of seismic interpretation. The traditional velocity analysis does not concern the velocity dispersion of seismic waves, but the dispersion characteristics is becoming an increasingly important attribute of reservoir seismic prediction and seabed exploration. Based on the time-frequency analysis technique, this paper presented a frequency-varying velocity analysis method for reflection seismic records, in which the frequency-varying velocity can be obtained by using the common depth point collection. On this basis, three different geological models were used to test the simulated seismic data. The results showed that the method presented in this paper can obtain accurate formation velocity of constant velocity and reasonable formation velocity of frequency variable velocity, which makes it possible to use frequency variable velocity to carry out more accurate dynamic correction and reservoir prediction.