In order to solve the problem of high Constant False Alarm Rate (CFAR) in single frame detection of radar clutter, a scan-to-scan accumulation algorithm based on velocity template is proposed in this paper.Firstly, velocity templates of different velocities and accelerations are constructed based on the movement characteristics of the targets, covering all the possible target trajectories.Secondly, the velocity templates are used to match different moving targets for making binary accumulation and detection judgment.During the accumulation, Doppler velocity information is used for assistant judgment, thus can further reduce the influence of the false alarms to detection performance.Finally, simulation results show that this algorithm can effectively suppress the radar clutter.