During operation, electrical equipment is always under the influence of various external factors, and its performance will constantly change. These external factors mainly include external electric fields, environment, high voltage, corrosion, and machinery. Under the influence of these adverse factors, electrical equipment is more prone to unpredictable faults, and even lead to power operation interruption. Therefore, insulation tests should be conducted on high-voltage electrical equipment in the power system before it is put into operation to ensure the safe and stable operation of the power system.