Abstract: Considering the refractive effects of different media interfaces, for underwater applications of laser synchronous scanning triangulation imaging system, the spatial three-dimensional coordinate measurement expression of the underwater synchronous scanning triangulation distance imaging system was obtained through theoretical modeling. The influence of the main parameters, such as the baseline distance and the receiving lens focal length, on the resolution of the distance measurement and the effect of the length of the imaging detector on the measurement range were analyzed. Through the simulation, we find that the increase of the baseline distance and the focal length of the receiving lens can improve the distance measurement resolution and the increase of the imaging detector length can increase the system measurement range. The simulation results show that increasing the baseline distance and the focal length of the receiving lens is beneficial to improve the resolution of the distance measurement, and the increase of the length of the imaging detector is beneficial to increase the system measurement range.The research work provides a theoretical basis for the design of the underwater synchronous scanning triangulation distance imaging system.