Abstract: The third-generation semiconductors are core materials to support 5G technologies, new energy vehicles and optoelectronic applications. In order to stimulate the interest of students in scientific research, a comprehensive experiment on preparation of double-heterojunction thin film and laser device is designed. The experiment includes the preparation of double-heterojunction thin film by means of metal-organic chemical vapor deposition, fabrication of the pump laser device and measurement of electro-optical properties. The experiment has a novel content and a wide range of knowledge. It has been proved that the comprehensive experiment has significantly improved students' abilities in experiment design, equipment operation, data processing and research paper writing, among others.