The utility model provides a protection device of material level detector, belongs to and gets rid of dust, the high temperature technical field to the influence of material level detector. This kindof protection device of material level detector includes the prober interface flange, and the prober interface flange is measured a section of thick bamboo and is connected feed bin flange, outer sleeve of suit on a measurement section of thick bamboo that is close to feed bin flange department. The gas mixture interface passes through pipe connection water spray generator and unfamiliar air pump,the water smoke air mixture that forms in water spray generator spouts the inner chamber of going into to measure a section of thick bamboo through the tangential wind gap and forms the vortex at a distance from hindering the dust in getting into and mixing the wind chamber. This protection device simple structure, convenient to use can reliably, effectively get rid of dust, high temperature andto the influence of material level detector, guarantee measurement accuracy, increase of service life.