Abstract: In order to improve the detection performance of underwater laser screen, the underwater laser light screen detection model was established according to the underwater beam propagation law. The detection performance of underwater laser light screen was analyzed based on Monte Carlo simulation method. The simulations were carried out based on the above underwater laser light screen detection model using MATLAB software to analyze the influence of attenuation coefficient of seawater, initial power and transmission distance on the underwater laser light screen transmission. The simulation results show that the smaller the attenuation coefficient of seawater, the smaller the impact of the transmission rate of the underwater laser light screen. When the seawater parameters and transmission distance are fixed, the initial power can only affect the final power reaching the detection end, but it has little effect on the transmission rate of the underwater laser light screen. When the seawater parameter is fixed and the transmission distance is 1m, the transmission rate is about 15% and is stable. When the transmission distance is increased to 30 m, the transmission rate is below 5%.