In the actual operation of power system, the high temperature of cable conductor often causes power system failure, but because the cable core temperature is not easy to monitor, therefore, a rolling prediction method based on LSTM (Long Short-Term Memory) is proposed to predict the cable core temperature. According to the collected cable core temperature data set, this algorithm is used to train the model, dynamically adjust the parameters of the network model, and study the law of the data change, so as to realize the prediction of cable core temperature. The results show that the RMSE of the algorithm model is 0.1979 °C, and compared with the BP and LSTM algorithm model, the algorithm model can effectively predict the short-term cable core temperature change trend, the results show that the algorithm has practical significance in the safe operation of power system.