By analyzing the structural performance characteristics of a heavy-duty gearbox, based on the modular design thinking and the requirements of the actual maintenance training application, the virtual prototype of a heavy-duty gearbox, such as the construction of three-dimensional model, collision detection, 3d observation, disassembly sequence planning and evaluation of training in the virtual maintenance training simulation platform and maintenance simulation implementation process. A desktop virtual maintenance training system based on EON simulation platform is constructed. The training results show that the system can accurately guide the trainees to complete the gearbox maintenance training tasks correctly, with good operability and interaction.