Applicable and effective compensation algorithm can improve the precision of rapid prototyping manufacturing. Based on analysis of present compensation algorithms, a point-by-point calculation compensation algorithm is developed in this paper. The rationality of intersection points of segments of compensation contour is checked point by point, and then the unreasonable points are adjusted. The compensation contours can be gotten. The calculation process of point-by-point calculation compensation algorithm is detailed introduced in this paper. The practicality of algorithm is tested and verified by examples.