In CNC (Computer Numerical Control) vocational colleges, the current traditional pedagogy has become conflicting with the learning preferences of the “Generation Z”, resulting in their low sense of competence, low learning autonomy, and insufficient recognition of industry identification. Thus, gamification design provides novel ideas for addressing these issues. Based on the theories of self-determination theory and motivational affordances, this study analyzes the sore points and study needs of students who are majoring in CNC technology at vocational colleges. Hence, according to the 12 dimensions of motivational affordances, the “needs-affordances-features” framework and the course content of CNC technology, a set of gamification design strategies for CNC machine tool skill training is proposed. Consequently, a smartphone-based interactive design practice is completed. Following this design practice, a user experience test is executed, and a positive result is obtained. Theoretically, this study explores the feasibility of modified gamification design processes that combine the motivational affordance model and the “needs-affordances-features” framework. Practically, the integration of gamification design into CNC machine tool skill training is not only a bold attempt to boost the learning motivation of students, but also a practical research foundation for the innovative development and transformation of CNC technology vocational education.