In order to evaluate and test the performance of processing arithmetic in single photon laser ranging,an emulational platform that can simulate real target echo and background noise is of great value.The construction and basic working principle of single photon laser ranging technology are introduced,and analysis is made to the models of target echo and background noise.M sequence is a frequently used digital pseudo-random signal.Based on this,a random sequence with adjustable scale is created,which can act as model of noise.A sequential logic circuit that can generate echo and noise signals is designed on FPGA chip,which can simulate the changes of moving speed and noise intensity.An ideal result is obtained in experimental verification.