Based on computer numerical control, a new technology of profile modeling- less camshafts grinding machine was developed. At the same time, open- architecture numerical control system based on IPC and position control mode of servo system was proposed to realize envelope principle of camshafts grinding. On the basis of mathematical analysis, several key factors to affect machining accuracy of camshafts was analyzed. As a result, many correlative problems were solved, such as geometrical relationship model, constant linear velocity grinding control, compensate of grinding wheel radius, multiple-constraints interpolation, digital servo and correlative circuit. To realize digital control of camshafts grinding, hardware interrupt technology whose working platform is Windows95 was researched on, and the control system was realized by following technologies, such as separating interpolation from real time servo, front-back real time communication control based on double buffers. The experiment of servo driving indicated that the project is feasible credible and propitious to be reconstructed into digital control of swing-beam camshafts grinding.