In order to make the industrial robots complete the cutting and machining processes of complicated workpieces accurately and efficiently, one algorithm for the robot cutting and machining processing paths directly generated by the three dimensional (3D) point cloud is proposed, which is combined with the point cloud technology and the robot technology. The point cloud measurement system with laser displacement sensors and industrial robots as its core units is constructed, and the extension from one-dimensional measurement to the 3D measurement is realized by the coordinate transformation. The 3D point cloud of the machined workpiece profiles is obtained by the on-line measurement, and the point cloud preprocessing algorithm and the robot path planning algorithm are adopted to generate directly the robot paths for the machined workpieces. The simulation results show that this measurement system and the algorithms can accurately extract the 3D point cloud of the workpiece profiles and quickly generate the robot processing paths.