The invention discloses a laser protective lens temperature detection device. The laser protective lens temperature detection device comprises a lens maintaining mechanism, a temperature sensor maintaining mechanism and a temperature sensor assembly; the lens is clamped on the lens maintaining mechanism; the lens maintaining mechanism is inserted in the temperature sensor maintaining mechanism; the temperature sensor assembly comprises a thermal resistor; the temperature sensor assembly is arranged in the temperature sensor maintaining mechanism; the thermal resistor is tightly contacted withthe lens under the action of the temperature sensor assembly; the lens maintaining mechanism is provided with a through hole; the center of the lens is positioned on the through hole; the temperaturesensor maintaining mechanism is provided with a light-transmitting hole opposite to the through hole position; and laser from an air knife is ejected after passing through the through hole and the light-transmitting hole. The laser protective lens temperature detection device can protect the lens, also can directly detect the real-time temperature of the protected lens and can judge the real-timestate of the protected lens through the temperature value and the temperature increasing speed; and through a large batch of temperature measuring tests, the temperature value of the protected lens under various operation states and the critical value of the temperature increasing speed are counted and analyzed.