Abstract: Fluid dynamics simulation of fluid jet polishing material removal mechanism was studied base on the Fluent software, and the pressure, velocity and wall shear stress of the flow were analyzed. It indicates that the material removal rate is dependent on the distribution of surface shear stress, and the removal function presents W type. The influence of the entrance velocity, operation distance and abrasive concentration on the polishing result was analyzed by using orthogonal test, the result shows that the material removal rate increases with the increase of the incident velocity and abrasive concentration, it decreases as the operation distance increases, and the operation distance has a significant impact on the removal rate. This work can be used for choosing process parameters in process investigation.