A summary of range imaging theory of MSM laser radar is introduced.The key system parts of the radar are designed,which include FM signal generator,AM laser transmitter,MSM self-mixing detecting circuit.The range performance and distance resolution experiments have been done based on single pixel which is chosen form 32×32 pixel array.And the results show that the distance resolution is 0.375 m with linear FM bandwidth of about 400 MHz.The work lays a good foundation for the development of practical range imaging radar.