PBL teaching model is a valid way which can resolve the degree of satisfaction of teaching method in specialty degree graduate student’s case course. In this paper, the PBL teaching model was applied into the case course of underground engineering construction and the concrete steps of PBL were detailedly expounded, include course content conformity, case design, PBL item design, plan, action, communication and evaluation. The difficulties of PBL were pointed out and the countermeasures were proposed. The PBL practice shows it can increase the student abilities of autonomic learning, independent inquiry, engineering practice and innovation. It is propitious to train student’s initiative spirits and group cooperative spirits.