In order to explore the influence law of oil immersion degree on churning loss in meshing area of gear of heterogeneous reduction box,the moving particle semiimplicit method (MPS) was used to simulate eight kinds of heterogeneous gearbox churning models and the churning models based on different steering and different oil immersion degree in gear meshing zone.The results show that the degree of oil immersion in the meshing zone is positively correlated with the oil fluctuation,velocity and oil churning loss.The oil churning in the meshing zone of the gear is larger in clockwise steering than that in counterclockwise steering.The change of steering and oil immersion degree leads to the change of oil content in the meshing zone,which leads to the change of gear meshing loss.The change of oil immersion degree can also cause the change of gear resistance loss,which indicates that the total oil churning loss is mainly affected by the change of parameters,and the proportion of gear meshing loss and resistance loss varies with the parameters,which requires a single or multivariate specific analysis.