Prefabrication technology is an advanced installation model which is advocated in mechanical-electrical industry. As an important measure of the mechanical-electrical construction enterprises′ advanced level, it becomes more and more popular in construction industry. Adopting the technology which combined BIM with production line of air duct prefabrication for air duct building project can improve the precision and production efficiency of prefabrication figure. It can also deepen the procession of air duct prefabrication. As a result of adopting this technology, we can further improve the installation quality of air duct prefabrication, shortenting work period and saving costs. This technology improves the management level of construction enterprise, and providing a new direction for the development of prefabrication.