Distribution transformer is an important equipment in distribution network. The running state of distribution transformer directly affects the quality, safety and stability of power supply. In order to improve the prediction speed of distribution transformer operation reliability and ensure the stable operation of substation equipment, a distribution transformer operation reliability prediction model based on big data technology is constructed. Calculate the reliability characteristic quantity of transformer according to the predicted demand. Setting logistics forecasting nodes based on power dispatching data results. Combined with big data technology, the orthogonal prediction matrix is constructed, and the prediction model is constructed by using big data redundancy processing method. The test results show that the response time is less than 1.3s, the prediction accuracy is 96.37%, and the model is stable. It is proved that the proposed method can effectively improve the reliability prediction effect of transformer and has practical application value.