Aming at some shortcomings of maintenance training on actual equipments, it developed half-practicality maintenance training system based on bus-mastering. Among the system, hardware sub-system and control software sub-system design and development of the master platform are key. Basic functions demand was analyzed, on the basis of which main technology indexes was designed. Control software sub-system was designed to include such four parts as control and demonstration, training check and evaluation, comprehensive training, signal flow control and display. Process design of each module of the four parts was implemented. This is significant to innovating equipments maintenance training manners and methods based on virtual reality and bus-mastering technology, and is significant to improving training effectiveness.