Traditional lubrication system design is mostly based on empirical formula for calculation and design,and then verified by test.Aimed at the long design cycle and high cost of traditional lubrication system design,a design method based on Flowmaster software was proposed.Taking a planetary gearbox as an example,the heat generation of each lubrication point in the gearbox was analyzed and calculated,and the lubrication system was preliminarily designed.The results show that the friction heat generated at the input gear is the largest,the oil demand of the input gear is the largest.The corresponding lubrication system model was built by Flowmaster software,and the steady-state and transient simulation of the lubrication system performance was carried out.The simulation results verify that the designed lubrication system can meet the lubrication demand of the gearbox.The transient simulation results show that the closing speed of the valve will affect the flow and pressure characteristics of the system.