Abstract: In the ultrasonic scan of workpiece surface, the ultrasonic probe is difficult to target with the detection surface. It is difficult to achieve in the planning of the track. The accuracy of the detection is low. This paper presents using meshing method to reconstruct surface based on the scan line. Its normal vector of scan point is based on non-parametric meshing point data of Z-map model. The automated inspection trajectory generation of ultrasound probe achieved. Finally, the model is verified by experiments.