Abstract: Aiming at the problem that the teaching of computer-aided manufacturing (CAM) in domestic colleges and universities still focuses on the training of commercial software application skills, this paper puts forward a reform scheme of practical teaching of CAM based on Python+3D Printing+CAM path planning. Taking the easy-to-learn and easy-to-use Python language as the programming language, and the simple and safe 3D printing as the application object of numerical control (NC) machining, this paper guides students to independently develop a set of small and practical 3D printing CAM package, realizing 3D printing path planning algorithms including model slicing, profile splicing, filling path generation, support generation and optimization, end face sealing, NC code generation, etc. Finally, the CAM system is tested and refined on the 3D printer. The teaching reform program has a certain degree of generality, which is suitable for all majors of science and engineering.