STEM is an educational concept that integrates multidisciplinary knowledge such as science, technology, engineering and mathematics, emphasizes interdisciplinary learning, and focuses on cultivating students′ innovative thinking and practical ability. Physics is an experiment-based discipline suitable for implementing STEM educational concepts. Under the guidance of STEM education concepts, we try to integrate science, technology, mathematics and engineering ideas into the design and production of the gravity car, improve the gravity car, and install a small generator in the car, which can not only demonstrate the conversion of gravity potential energy into kinetic energy, but also demonstrate the conversion of gravity potential energy into electrical energy. Through the exploration of interdisciplinary practical projects, students can understand the links between different disciplines from more perspectives.