The performance of mechanical seal has an important influence on the thermal control efficiency and stable operation of marine core equipment of submarine hybrid pump.Based on the working state of the hybrid pump and the service environment of the mechanical seal,the three-dimensional model of seal ring-liquid film multi-body structure was established.Considering the multi-field synergy of thermal effect,force effect and fluid effect,the performance change law of seal ring-liquid film multi-body structure under simulated actual working conditions was studied by using thermal-fluid-solid coupling numerical simulation technology,and the lubrication characteristics,mechanical characteristics and temperature characteristics of seal ring-liquid film multi-body structure under different working conditions were obtained.The results show that in the multi-body structure of the seal ring-liquid film,the maximum deformation and maximum temperature of seal ring appear in the spiral groove area.With the increase of speed and pressure,the seal opening force and leakage increase,but the influence of speed is obviously greater than that of pressure.The influence of pressure on stress is significantly greater than that of speed,especially when the pressure exceeds 6 MPa,the contact pressure of sealing face is relatively uneven.Due to the effect of convective heat transfer and air flow viscous shear,the speed has a greater effect on the temperature of the seal end face than the pressure,especially in the low speed region of 500 r/min,the temperature of the ring-liquid film multi-body structure exceeds 75 ℃,and the temperature difference at different radial positions is also very obvious,which will cause damage to the mechanical seal.