The utility model provides a real empty room temperature detects thermocouple protective device, belongs to industrial instrument's application. Mainly solve in the real empty room of RH refractory brick drop with real empty room in the slag drop and injure thermocouple ceramic bushing by a crashing object, damage the problem of thermo -well. Protection device includes thermocouple, cylindric tubular metal resonator, the cylindric tubular metal resonator install in real empty room thermocouple attachment downtheholely, the thermocouple attachment is in the cylindric metal sleeve. The easy installation and maintenance of the device, it is high to detection ring border temperature, use ceramic bushing's thermocouple can play fine protective action, the thermocouple consumption can significantly reduce.