Open. Four of the seven university libraries in Qingdao are open to the outside world, and their lending systems are different. Among them, the library of Petroleum University has been open to the outside world for a long time, and its lending system is relatively perfect. 20 1 1 After all the schools moved to Qingdao, the library began to open to the citizens of the island city. In principle, it is open to all citizens, but easy to manage. Citizens who apply for library cards need to have a fixed occupation, and their units provide letters of introduction. From 20 14, petroleum university began to issue new alumni cards to graduates, which have the functions of spending and borrowing books on campus.