The numerical simulation of ship wake laser scattering mechanism and the detection process are important foundations for the laser detection and guidance of the ship wake. The feasibility that Monte Carlo method is introduced into the numerical simulation of lidar of ship wake is analyzed firstly. The Monte Carlo simulation model of laser detection of ship wake is developed with the actual parameters of self-developed lidar of ship wake. The causes of the large variance and low photon utilization of simulation results are in-depth analyzed by statistics on the simulation results. To resolve this problem, the method of photon collision forced in the receive optical fields, the photon splitting method with the total free pach of photon serving as a criterion, and the conbination of the two methods are put forward based on partial sampling theory and the basic principle of division-roulette bet. The comparative analyses of the simulation and the experimental results show that the proposed model simulation results fit to experimental data better, thus the correctness of the model is verified. The photon collision forced in the receive optical field and division-the roulette method can effectively reduce the variance and increase the photon utilization. In this paper, the Monte Carlo method is introduced into the simulation process of lidar of ship wake.