Abstract: Professional skill appraisal (machinist) is a professional development course for for obtaining railway vehicle machinist certificate. The course is highly practical. However, there are some problems in railway vehicles, such as large volume, heavy weight, difficult disassembly, difficult assembly and so on. The traditional teaching method is difficult to effectively solve the contradiction between the difficult understanding of mechanical structure and the high requirements of practical operation. The teaching method based on 3D scenario modeling makes full use of 3D scanning and 3D printing technology to realize the interactive mapping of online and offline resources. The teaching method deepens students' cognition of internal structure, improves their hands-on operation ability, and improves the passing rate of skill examination.

Key words: Digital Twins, Scenario modeling, Interactive mapping, Professional skill appraisal (machinist)