In order to improve the structure of middle reducer and realize the reasonable installation and layout of oil collection tank,the flow field of middle reducer splash lubrication in the nonorthogonal spiral bevel gear was simulated by using the software of Fluent and based on dynamic mesh technology.The results show that the numerical simulation method based on moving mesh can simulate the flow field inside the reducer.In the condition of two gears immersed in the oil,the lubricating oil runs faster after it passes through the gear engagement point,while the speed of reducer has a little effect on the overall trend of the flow field.The pressure is positive on the engagingin side and negative on the engagingout side,and the absolute values of pressure are increased on the engagingin and engagingout sides as the rotational speed increases.