Partial discharge monitoring of power cables is an important technical means to ensure the safe operation of cables. However, the traditional cable monitoring method is difficult to apply to the cable network system with complex feeder structure, wide distribution area and more cost-sensitive. To solve this problem, a cable insulation state sensing technology based on Internet of Things (IOT) technology is proposed in this paper. Firstly, considering scalability and accessibility, the overall framework of wireless sensor network for cable partial discharge monitoring is designed; secondly, the technical requirements of sensor nodes, low power management, data communication and other basic units of Internet of Things sensor network are analyzed; finally, based on the above research, it is realized. Distributed IoT monitoring for high frequency current of partial discharge in power cables. The system has broad application prospects in the on-line monitoring of partial discharge in cables