Abstract: According to the structural characteristics of the curve,a new polygonal approximation algorithm based on corner detection is proposed by introducing a polarization cornerity index for the corner candidate.This algorithm has nothing to do with the position of the start point.A comprehensive analysis between the polygon approximation approaches and the corner detection approaches for the reconstruction of the curve is executed.The newly developed curve reconstruction algorithm was extensively tested on various shapes and is proved to be computationally fast and robust to noise.Experimental results are stable and closer to human visual effects.