In order to solve the problem that the echo dynamic range is far greater than the range of the linear amplifier, this paper presents a short-range dynamic laser echo ranging approach. This method could generate wave by the FPGA and high speed DAC circuit, and then the STC (sensitivity time control) circuit could weaken the influence of the large echo dynamic range. Theoretical calculation and experimental results show that this scheme can be used for short-range laser radar echo processing, which not only can extend the distance of the dynamic range, but also can improve accuracy ranging. This method would be widely used in short-range laser radar systems.