This paper studies some key technologies of CNC system for cam grinding. The mathematical motion model for cam grinding is established according to the harmony of re-ciprocating motion of the grinding wheel and the rotating motion of the workpiece. The method of using the linear servomotor to accomplish the grinding wheel tracking is devel-oped and the dynamic model of the system is analyzed. Then the cross-coupled biaxial error compensation model is proposed. Finally,the hardware and software of the control system are designed based on open architecture. Some algorithms, such as spline fitting and inter-polation for cam contour, velocity control and feed control,are presented to improve grinding precision. This paper studies some key technologies of CNC system for cam grinding. The mathematical motion model for cam grinding is established according to the harmony of re-ciprocating motion of the grinding wheel and the rotating motion of the workpiece. The method of using the linear servomotor Then the cross-coupled biaxial error compensation model is proposed. Finally, the hardware and software of the control system are designed based on open architecture. Some algorithms, such as spline fitting and inter-polation for cam contour, velocity control and feed control, are presented to improve grinding precision.