State monitoring data of electrical equipment have strong correlation due to the strong coupling between electrical primary equipment in power station. On the basis of summarizing the theoretical knowledge and the propagation mechanism of abnormal signals, a correlation method for state data of electrical primary equipment is proposed. Through the horizontal and vertical correlation advantages of the monitoring system, the correlation between monitoring data and the abnormal situation is determined. The monitoring data are effectively correlated and provided to operators for abnormal diagnosis and analysis, which solves the problem of the lack of correlation analysis between primary equipment, and it makes certain practical application value.