Abstract: The airborne multi-pulse LADAR target signal simulator was studied based on signal model to evaluate the performance of laser echo signal processing algorithms and their digital hardware platform. Firstly, the main elements of target signal model and two definition of SNR were pointed out. Subsequently, based on the ladar equation and 1.064 um laser radiation photoelectric receiver experiment, the signal waveform was obtained and the target signal composition was analized. The echo signal model was further established by the analysis of air target echo pulse broadening. Then, the method to generate echo signal according to SNR was proposed based on the RMS value standardization of echo noise samples. Finally, the implement of target signal simulator was given based on FPGA and high-speed D/A and USB2.0 data transmission, which could provide the echo signal and sync -signal of static and dynamic targets with the SNR of 1-9.