Abstract: It is insufficient to describe maintenance process and relevant resources with existing modeling technique, and existing methods are deficient to combine the expression of maintenance task and maintenance action simulation. Therefore, MTN (maintenance task net) was proposed in order to solve the integration of maintenance task description and maintenance action simulation.The framework of MTN including definition module, drive module and control module was constructed. The three key factors of MTN including state, action and condition based on the style of Petri net was biult. State could define maintenance resources such as human, tools and equipments.Action could define simulation process of behavior.Condition decided the constraint of state and action. MTN could drive virtual scene display system to run simulation and also could control the whole process. A case of LRU(line replaceable unit) disassembly was applied and the result proves that MTN model is valuable for the simulation and analysis of maintenance task.