In order to improve the precision and efficiency of teach-and-play-back programming for laser machining, and overcome the structural limitation and the manual deficiency of the old system, a programming system is presented by adopting the concept of borrowed-machine measurement to integrate the laser scanning measuring probe and the CNC system. Here's the key technology to change the measurement of surface normal vector of machined surface into the measurement of points. And, it also addresses the measurement of free-form trajectory on 3-dimension surface in detail.