Due to its tendency of large automation and complicated structure, mine explosion-proof electric wheel dump truck makes the equipment fault maintenance harder; therefore according to the actual requirements, the online condition monitoring and fault diagnosis system is designed in this paper. In the system, in order to improve the reasonable and effective data collection and transmission, the system adopts CAN bus network architecture, and meanwhile the system uses the high performance digital signal processor TMS320F2812 as the controller of information unit and the state monitoring. The streamlined real-time multitasking embedded operating system DSP/BIOS is adopted on the condition monitoring controller, which will meet the needs of concurrent multitasking. The management system based on fault diagnosis expert is designed on the upper machine. Experiment shows that the system can meet the design requirements.