Atmospheric optical effect is one of the important factors that affect the performance of lasers.Based on the multilayer phase screen method,a large number of numerical simulations are carried out for laser horizontal transmission in the marine atmospheric environment.By superimposing the phase change caused by the attenuation and the thermal blooming on the turbulence phase screen,the influence of the three factors on the laser transmission characteristics is considered comprehensively.The changing rule of the laser radius,centroid shift root mean square and energy circle rate under situation of different laser initial power,different refractive index structure constants,different visibility and presence or absence of thermal bloomingwere analyzed.The simulation results show that the stronger the laser initial power,the more obvious the thermal blooming effect,the more serious the spot distortion and the worse the beam quality;the larger the refractive index structure constant is,the stronger the turbulence effect is,the more obvious the spread of the spot and beam drift,the decrease of average power density and the increase of the energy circle rate;the smaller the visibility,the more serious the laser energyattenuation,the greater the energy circle rate;the thermal blooming effect will increase the spread of the spots,increase the beam drift and the energy circle rate.The research results can provide a theoretical basis for the evaluation of the effectiveness of the laser at marine atmosphere.