The invention discloses a power cable fault monitoring platform. The power cable fault monitoring platform comprises a fault detector arranged on a cable line, a signal return mechanism arranged in a cable duct, a monitoring center and a movable monitoring unit connected with the monitoring center, wherein the movable monitoring unit comprises an overhead track formed in the cable duct, a moving mechanism arranged on the overhead track and a monitoring terminal arranged on the moving mechanism, the signal return mechanism comprises a communication line arranged in the cable duct and a plurality of data interface modules formed in the communication line, and the fault detector is provided with a first wireless communication module. The fault detection of the whole cable and monitoring environment information and device information in the cable duct can be achieved only by using a small number of sensors, an online current mode is acquired in real time through the fault detector to conduct comprehensive monitoring on line faults, and fault judgment is more timely and accurate.