Virtual maintenance is a new method of maintenance technology, which has deficiencies in disassembly planning, especially in the constraint of ergonomics factors and the hierarchical division of the components. On the basis of Petri net, the interpretative structural model is introduced to divide the equipment components and simplify the description of the maintenance disassembly process. In order to ensure the feasibility of the disassembly sequence, the ergonomics factors are introduced, which can be evaluated by jack platform. Genetic algorithm is used to define the planning objectives, constraints, codec in the process of virtual maintenance disassembly, and a certain type of gearbox is taken as the experiment evaluation, which verifies the high-efficiency of the designed algorithm.