The paper first demonstrates some relevant concepts with virtual maintenance, and further discusses the concepts and connotations of virtual maintenance. As the key techniques, virtual maintenance model and simulation method are studied in the paper. Virtual maintenance model (VMM) is present, and the model is based on Petri Net and can describe the relations of maintenance resources. In addition, virtual maintenance simulation rules are built in the paper. Finally, a case study of the LRU repair of an aircraft is conducted, and the result confirms the validation and feasibility of all the studies, which can become a new technique means for maintainability engineering.