The movement of lubricating oil in the gear box has a great influence on the power transmission and cooling performance of the mechanical rotating parts.Based on a highspeed gearbox of independent development,the flow field and pressure field of lubricating oil was analyzed by simulation,the equations were solved by utilizing RNG-k-ε ending flow model,including continuous equation,flow equation,turbulent energy equation and turbulent dissipation rate equation.By simplifying the gearbox model,the simulation analysis of the model was carried out by using the dynamic meshing theory and discrete PRESTO method,and the calculation results at different operating conditions were analyzed.The flowing characteristics in inlet holes of gearbox were obtained according to the analysis result,and the actual lubrication flowing of different bearings were also obtained.These results can be used for quantitative analysis of optimal bearing lubrication oil level,which also provide a theoretical reference for the structure design and systematic improvement of gearbox.