Aiming at the problems of complex distribution and the lack of comprehensive and effective pre-warning methods for power cables, a cable temperature pre-warning system based on the Gray Markov model is proposed. Firstly, the overall structure of the temperature pre-warning system and the data communication method are analyzed. The communication method combining Long Range(LoRa) and General Packet Radio Service(GPRS) is utilized to ensure the reliability of data acquisition. Secondly, the gray Markov model is adopted to predict the cable temperature. The prediction result is collected for fault identification in a cable temperature pre-warning model to improve the accuracy of the pre-warning system. Finally, the feasibility of the cable temperature pre-warning is verified by experiments and an early warning platform is built for cable temperature classification. The timely notification of various faults to enterprise management personnel is realized by this means.