Numerical simulation of the resistance and sailing state of high speed amphibious vehicle in still water was conducted with the finite volume method based on Reynolds averaged equation to obtain the resistance characteristics of high speed amphibious vehicle in water. The mesh convergence of mesh was discussed by comparing the resistances of different mesh densities, and the numerical calculation method was validated by comparing the simulation results with model test results. In addition, the different resistance components of the amphibious vehicle were analyzed based on the calculation results of the multiple molding. Then, the changes of resistance and sailing states of the amphibious vehicle model with openings were calculated and analyzed. The results show that, for the amphibious vehicle in transition stage, the proportion of wave-making resistance to the total resistance increases with the increase of velocity (the maximum rate can reach over 60%), the proportion of viscous pressure resistance to total resistance is 30%~40%, and the proportion of friction resistance to total resistance is less than 10%. The resistance increases when the amphibious vehicle added with openings, and the resistance increases by about 11% and the draft increases by about 5% when Fr▽ is 1.297. Compared with the amphibious vehicle model with non-openings,  the amphibious vehicle model with openings shows changes in proportions of different resistance components to the total resistance: the proportion of wave-making resistance decreases and the proportion of viscosity-pressure resistance increases.