Abstract: In the diagnosis of electrical equipment circuit faults in thermal power plants, a single electrical equipment status characteristic is difficult to reflect the real-time status of the electrical equipment, resulting in low diagnostic accuracy of existing methods. To solve this problem, a fault diagnosis method for electrical equipment circuits in thermal power plants based on PLC and configuration technology is proposed. Under the joint action of PLC and configuration technology, a power plant electrical equipment status monitoring architecture is constructed to collect real-time electrical equipment status data, mine electrical equipment status characteristics such as kurtosis, power spectral density, and harmonic content from the collected data, calculate the comprehensive characteristics of electrical equipment status data, and achieve the discrimination of electrical equipment fault status. Based on this, SVM algorithm is introduced, kernel function is set, and the type of electrical equipment circuit fault is diagnosed. The experimental results indicate that the designed diagnostic method has an AUC value of 0.97 and a misdiagnosis rate of 1.59% in practical applications, demonstrating high diagnostic accuracy.