Graduation design plays a very important role in cultivating the ability of building electricity and intelligence students to comprehensively use the basic theory, basic knowledge, basic skills and solve practical problems. The multi---major graduation can not only promote the communication between different universities, but also strengthen the construction of this major and expand its influence. Based on the analysis of the seven-year practice teaching mode of the joint graduation design of building electricity and intelligence, this paper discusses the interactive teaching practice of colleges and colleges, colleges and enterprises, and puts forward corresponding suggestions for the existing problems, so as to broaden the students' horizons, realize the mutual benefit and win-win situation of multiple institutions, promote the mutual benefit between teachers and students, implement the concept of sharing educational resources and promote the innovation of multi-dimensional practice teaching mode of collaborative education.