Fluid Jet Polishing (FJP) can obtain atomicscale roughness and damagefree surface,which has been considered to be one of the most potential techniques for the ultrasmooth processing among a variety of surface processing technologies.In FJP,the impact angle is one of the important parameters that influence the polishing quality.Using selfdeveloped FJP device,the effects of the impact angle on the surface morphology and the material removal were investigated in the fixedpoint impacts.The experimental results show that the shape of the material removal becomes more and more asymmetric,the material removal rate is gradually reduced,and the maximum removal depth appears a monotonous change with the decreasing of the impact angle.The influence mechanism of the impact angle of the jet on the material removal was analyzed by combining the flow field distribution of FJP and the collision angle of the particles.The results show that the influence of the impact angle of the jet on the material removal can be attributed to the change of collision angle and the collision frequency of the particles.Larger collision angle and more particle collision will result in a greater amount of material removal.The combined effects of these two factors affect the volume and the profile of the material removal.