A method for automatically generation of 5-axis 3D laser cutting path was proposed based on automatic recognition of incision features. Automatic selection of incision features was realized through automatic recognition of incision features using STL (stereo lithography) model. The laser beam radius compensation was done by offsetting of the edge loop of incision. The positions of laser beam focal points were decided according the discrete points on the edge loop of incision. The laser head posture was determined using the normal vector of triangle face on which the laser beam focal points was located. The case studies indicate that the method can automatically select incision features and carry out laser beam radius compensation automatically,at the same time can ensure the laser head perpendicular to the surface of workpiece all the time. The operation of software system is stable and reliable.