This paper aims at range and error calibration of laser speedometer. According to the measurement principle of laser speedometer, one new calibration method and instrument with simulated target is put forward, which provides simulated target with invariable speed to simulate vehicle, and achieve range calibration by changing the speed of simulated target. Experiments show that the calibration instrument can meet the need of laser speedometer calibration because of its wide calibration range, high repeatability and universal performance.