Laser cutting head protective lens mounting module capable of detecting existence or inexistence of protective lens

The invention discloses a laser cutting head protective lens mounting module capable of detecting existence or inexistence of a protective lens. The laser cutting head protective lens mounting modulecapable of detecting existence or inexistence of the protective lens comprises a sensor mounting base, an LED mounting base and a protective lens mounting base, wherein a sunken groove is formed in the upper surface of the sensor mounting base; the LED mounting base is fixedly arranged below the sensor mounting base; the protective lens mounting base is embedded in the lower surface of the sensormounting base and can be drawn out of one end of the sensor mounting base; an annular cylinder body is fixedly arranged in the sunken groove; a red light emitter and a red light receiver are symmetrically arranged on the annular cylinder body; red light is emitted to the protective lens in the protective lens mounting base by the red light emitter and then is emitted to the red light receiver after being refracted. The las