Abstract:High speed spindle is easy to be heat and deform that affects the accuracy of CNC machine in the working process, and the angular contact ball bearing, as the supporting part of highspeed spindle, plays an important role.According to Hertz contact force theory, an analysis model that angular contact ball bearing affected the spindle displacement was established with the force balance equation and displacement equation of angular contact ball bearing.Then, the displacement value of the shaft sleeve calculated by using the model was compared with that measured by the displacement sensor to verify.At last, the influence for contact force of inner and outer rings, stiffness of bearing was analyzed and calculated under different speeds, as well as the influence on the shaft sleeve and shaft displacement.The model can be used to set reasonable preload and spindle speed, to improve positioning precision of shafting and to provide reference for bearing preload, working pretightening load adjustment and pretightening device design, weakening the thermal deformation caused by plastic deformation of bearing, which reduces the influence on the deformation of high speed spindle.