Abstract: To improve the reliability of urban rail transit traction substation, TEV (transient earth voltage) instantaneous value, ultrasonic instantaneous value, SF6 (sulfur hexafluoride) pressure gauge pressure, SF6 pressure gauge temperature, SF6 pressure gauge density, switch contact point temperature, and cable joint temperature are selected as evaluation indicators for traction substation SF6 switchgear. A comprehensive evaluation model of traction substation health status is established. Taking the traction substation demonstration station established by an urban rail company in eastern China as the research object, the realtime monitoring data of various evaluation indicators of the traction substation in actual operation are sorted and analyzed. The weights are determined by combining the AHP (analytic hierarchy process) and EWM (entropy weight method), and the evaluation indicators that have a significant impact on traction substation health status are obtained. The health status scores of the traction substation in different periods are also evaluated. Results show that among the factors affecting the SF6 switchgear, switch contact point temperature has a great impact on traction substation health status. The southern region of China is the most humid in February, March, and April each year, and the temperature is higher in July and August, all are not conducive to the healthy operation of urban rail traction substation. The monitoring of the switch point contact temperature should be emphasized, and the maintenance and repair of traction substation should be carried out to improve its health status and ensure that it operates in a good environment.