Abstract: The existing look-ahead algorithm for NURBS curves is not accurate in determining the starting point of adaptive deceleration area,and the deceleration distance produced is longer than the actual need.In order to avoid this problem,and to prevent the interpolation generates low-speed regions,a method based on reverse interpolation area is given to determine the starting point of deceleration area.In this method,the look-ahead algorithm using S-acceleration planning reversely interpolates the curve and establishes the cross-range with velocity curve of adaptive interpolation.Then the curve is re-interpolated from the starting point of the cross-range to obtain the ideal velocity planning scheme of the deceleration zone.Experimental simulation results show that the algorithm proposed in the paper can effectively avoid the phenomenon of low-speed region in the interpolation process,and improve the interpolation efficiency as well.