The invention discloses a fast intelligent programming method for a spraying robot for planar/approximate planar workpieces. Firstly, laser is adopted to scan the surface of a workpiece to acquire a set of original point clouds, the point cloud of the workpiece is then intercepted, the point clouds are simplified and noise points are filtered; secondly, a two-dimensional plane point cloud representing the spraying surface is separated from a three-dimensional point cloud, the polygonal boundary features of the point cloud are further extracted, and straight line fitting is carried out; thirdly, the boundary polygonal features of the spraying surface are extracted through operations such as polygon fitting, correction and vertex sorting; and finally, the full-coverage path on the surface ofthe workpiece is planned. According to the fast, intelligent and de-teaching programming method for the planar/approximate planar workpieces, a tedious manual teaching process is not needed, the workpiece surface features are extracted through automatic scanning of low-cost 2D line laser, the full-coverage path of the robot is automatically optimized and generated, and the spraying efficiency andthe spraying operation quality of a specific workpiece surface can be effectively improved.