Aiming at a typical fault case of a spacecraft power supply temperature control system, an anomaly detection method based on Pearson correlation coefficient regression analysis is proposed. Firstly, the feature extraction of relevant telemetry data is carried out. Secondly, the normal telemetry data are fitted and modeled, and the subsequent telemetry data are detected by the model. Finally, the regression analysis method based on Pearson correlation coefficient is used to simulate the measured data. The results show that the method can quickly extract the abnormal phase from the multi-dimensional telemetry data for unknown spacecraft anomalies, it can be applied to other spacecraft.