For virtual simulation demand of three dimensional sheet metal pieces laser cutting and the shortcomings of the current laser cutting process simulation system, with gantry five-axis machine tools, vertical axis robot and upsidedown six-axis robot cutting platform as sample, multi-platform three-dimensional sheet metal laser cutting process simulation system, including virtual machining scene 3D visualization, machine kinematics calculation based on site data, laser cutting technology and processing code output is developed. Configuring node sequence to realize virtual machining scene construction, based on Nurbs surface fitting, this paper realizes the mapping of the cutter site data with the shape of nonvertical sidewall cutting. Based on the cutter point data, the laser head pose matrix is solved, and the D-H motion coordinate system is established to realize the kinematics calculation of the machine tool and the simulation of machine tool motion. The process of cutting process is established, and the cutting process is realized, including the embodiment of cutting process defect, the detection and processing of interference collision, and the display of the transition trajectory between the cutting ring. Finally, corresponding reliable platform processing code is output.