In order to optimize and improve the lubrication system of middle drive axle main reducer for one heavy vehicle,an optimization solution which adds oil spoon and track in original gearbox shell was presented.The Moving Particle Semiimplicit (MPS) meshfree particle method was used to analyze the lubrication effects of this optimization solution.With the spur and bevel gear as research objects,the splashing and velocity distribution of lubricating oil under two typical conditions of high speed and low speed were gotten.The results show that the lubricating oil can reach to the related parts including bearing and differential by oil spoon and track both in two typical conditions,and the lubrication effects is improved,which verify the feasibility of this lubrication solution.The MPS is successfully applied to the lubrication analysis of the reducer,which provides a new method to analyze lubrication system