In this paper, the Arrhenius model and the environmental and reliability influencing factors of the comprehensive state evaluation of the maintenance degradation factor are adopted, and the combination coefficient of the operating state quantity and other state quantities is determined by the probability of missing judgment of the operating state quantity, and the state evaluation method is proposed to realize the scientific expression of the impact of the three elements of environment, reliability and operating state quantity on the relay protection state, which is more suitable for the actual operation status of the relay protection equipment than the existing technology, and assists the operators of the relay protection equipment to take scientific and effective disposal and response measures. It has a good supporting effect on equipment maintenance and technical transformation.