For the safe and stable operation of electric vehicle DC charging piles, this paper proposes a charging pile fault prediction algorithm based on improved support vector machine. The algorithm first performs preprocessing such as missing value filling and normalization in the operating parameters of the charging pile; then the preprocessed data is input into the support vector machine model for training, and then the firefly algorithm is introduced for improving the sparrow algorithm to search for the parameters for the support vector machine model. The optimal model is obtained; finally, the obtained optimal model is using to predict and diagnose the operation state for the charging pile to do judge whether the charging pile is faulty. The experimental results show that the prediction accuracy of the prediction algorithm in this paper could reach 94.68%, which is much higher than 72.34% of the traditional support vector machine model.