In the actual laser detection process of ship wake, there are impurities (bubble groups, suspended particles) between the laser detection system and the target bubble layer, resulting in the reduction of the signal-to-noise ratio of bubble echo signal. In order to improve the signal-to-noise ratio of the actual ship wake detection, Monte Carlo method was adopted to simulate the occlusion of different bubble layer characteristics. By changing the thickness and number density of the occlusion bubble layer, the influence of the occlusion bubble layer on the target bubble echo characteristics was explored. The simulation results show that when the occlusive bubble layer exists, the echo signal decreases obviously, and the decreasing trend is more severe with the increase of the occlusive bubble layer thickness and number density. A simulation ship wake laser detection system was built under laboratory conditions, and the occlusion of different bubble layers was verified. It is concluded that the occlusion effect becomes stronger with the increase of bubble layer thickness and number density. The normalization of test data is carried out to realize the mutual verification of simulation and experiment, which can provide support for the engineering of ship wake laser detection.