Abstract: The effect of target radial motion on stepping frequency pulse signals is analyzed.The analytic result shows that the echo is distorted due to the motion.For solving this problem,the quadric velocity compensation method is advanced.Under the condition of few sample points,this method could reduce the searching range based on the preliminary velocity estimation value and compensation accuracy value.So the method is satisfied with the requirement of accuracy.The simulation results and performance analysis manifest the method possesses the stability and fewer computation load,and it is convenient for real-time processing.