Abstract: High vacuum gate valve is widely applied to the vacuum subsystem of space environmental simulator, such as cryogenic pump, molecular pump inlet valve, rough unit master valve, etc. All these valves are single-point-of-failure equipment or the critical equipment which would exert a great impact on the operation of testing system in the event of failure. This thesis focuses on single-point-of-failure equipment rough master valve of KM6 space environmental simulator testing system, and develops a study of the working status monitoring method. Through displacement sensor, valve's opening and closing time under specific conditions, switch in-position indicator and sound sensor, the status of the valve is monitored and judged from multiple perspectives. Besides, the relevant data can be given before the failure occurs and its status can be predicted, which acquires better effect.