Abstract: For difficult manual maintenance of coordinate control system of main coal transport route, a fault diagnosis module for the system was developed, and fault diagnosis principle of the system was introduced from aspects of equipment-level diagnosis, system-level diagnosis and remote diagnosis. The equipment-level diagnosis records important events of sensors, intrinsically safe power and so on, and sends the records to coordinate controller of the system. The system-level diagnosis times each equipment in the system uniformity, and adopts the coordinate controller to analyze fault cause through fault diagnosis algorithm and send the analyzed results to centralized control room on the ground. The remote diagnosis is analyzing and confirming fault cause through engineers in the centralized control room or developers in equipment manufacturing enterprise, so as to notify inspectors to remove fault.