A method for simplifying a point cloud is provided. The method includes: (a) acquiring a point cloud; (b) establishing a topological structure for the point cloud; (c) selecting a maiden point from the point cloud as a selected point; (d) searching a plurality of points which are near to the selected point from the point cloud according to the topological structure as near points of the selected point; (e) fitting the selected point and the near points to form a paraboloid, obtaining curve equations of the paraboloid, and computing a curvature of the selected point according to the curve equations and a curvature formula; (f) repeating the steps from (c) to (e) until the curvatures of all points in the point have been computed; and (g) simplifying the point cloud according to the curvatures of the points and a preconfigured parameter. A related system is also provided.