Abstract: In order to improve the friction characteristics of the friction pair, find the flow state of particles in the oil film and the temperature distribution of oil film in flow distribution pair, the effects of solid particles in the oil on the oil film characteristics and volumetric efficiency of high-pressure vane pump were studied by means of theoretical analysis, numerical simulation and experimental test in this paper. Firstly, the two-phase flow calculation model was established, and the particle gravity equation and motion resistance equation were established also. Then, the passage model of flow distribution pair was set. The fluid domain of flow distribution pair included the oil port, groove and oil film. The passage model was meshed and the boundary conditions were set. According to the relevant standard of cleanliness requirement of hydraulic fluid system, the solid particle diameter was selected as 0.005, 0.010 and 0.013 mm, and the solid-phase volume fraction was selected as 0.2%, 0.6% and 1% for calculation. Finally, the influnce of solid particle diameter, solid-phase volume fraction and operating parameters on the flow field characteristics of oil film were analysed by FLUENT software. By changing the diameter and solid-phase volume fraction of solid particles, the working pressure and rotating speed of the pump, the nephogram of solid-phase volume fraction distribution and temperature distribution of the oil film in the flow distribution pair were obtained by numerical simulation and verified by test. The result showed the addition of solid particles in the oil had no effect on the pressure value and distribution of the oil film, but it leaded to the decrease of the oil film temperature in the oil discharge area, and the maximum change of oil film temperaturewas 2 K. The solid-phase volume fraction of oil film in the oil suction area decreased with the increase of particle diameter with the maximum change of 0.25%, while it increased in the oil discharge area with the maximum change of 0.35%. On the whole, the solid-phase volume fraction of oil film changed in the increasing trend, and the maximum change was 0.72%. The volumetric efficiency of vane pump decreased with the increase of solid particle diameter, and the relationship between them was approximately linear. With the increase of the solid-phase volume fraction of solid particles, the solid-phase volume fraction of oil film increased, which resulted in the decrease of volumetric efficiency of vane pump. The relationship between solid-phase volume fraction and volumetric efficiency was nonlinear. The surface temperature of oil film decreased with the increase of solid-phase volume fraction. The position of maximum change of oil film temperature was oil discharge area, and the maximum change was 2 K. The solid-phase volume fraction of oil film decreased with the increase of working pressure, and the maximum change was 0.3%. The temperature of all areas on the surface of the oil film was increased, and the temperature change of the core area was 4 K. The solid-phase volume fraction and temperature in most areas of oil film increased with the increase of rotating speed. The maximum change of solid-phase volume fraction and temperature of oil film was 0.2% and 3 K respectively in the areas with great effect. This research provides a reference for the flow distribution pair design of the port pair of high-pressure vane pump when the oil contains solid particles.