In order to realize smooth transfers along a continuous segment trajectory,  adjustable form of the cubic spline connecting curve was made for corner transition. The movement speed remains unchanged during the process of corner transition, changing the form adjustment coefficient of the spline connecting curve to adjust its curvature radius and controlling the value of acceleration. The results show that this method of adjustable form of the cubic spline connecting curve control corner transition can guarantee the smoothness of the path and the continuity of the speed and improve the machining efficiency, and reduce the acceleration mutations effectively, lessen the impact to machine tool.