The invention belongs to the field of intelligent substation auxiliary control system monitoring, and particularly relates to an intelligent substation auxiliary control system wireless temperature and humidity sensor and a monitoring method. The intelligent substation auxiliary control system wireless temperature and humidity sensor is characterized in that a signal acquisition sensor, a processing circuit, a real-time clock system, a wireless communication system and a controller system are arranged on a core circuit board arranged inside an outer shell, and a display system, a waterproof knob and an antenna are arranged on the outer shell; the waterproof knob is connected with a power supply cable; the signal acquisition sensor is connected with the processing circuit and then sequentially connected with the real-time clock system, the wireless communication system and the display system to the controller system. The intelligent substation auxiliary control system wireless temperature and humidity sensor is compact in structure and attractive in appearance, the installation method is easy, convenient and safe, operating personnel can install, use and maintain the intelligent substation auxiliary control system wireless temperature and humidity sensor conveniently, intelligent control over the temperature and humidity of indoor environments can be achieved, and the defects that networking is difficult and expansion is inconvenient in a wired communication method can be overcome. The intelligent substation auxiliary control system wireless temperature and humidity sensor is wide in application range and can be applied popularly especially in unattended substations.