The utility model relates to an inferior nature health supplies machinery especially relates to a novel dust exhausting fan, the lead powder collecting box comprises a box body, the front end of box is equipped with a guide dish that leaks hopper -shaped, be equipped with a plurality of filtration pores of crossing on the inclined plane of guide dish, the middle part of guide dish is equipped with an air pipe, be equipped with a support frame on the front end of box, the middle part of support frame is equipped with the motor, be equipped with the flabellum in the pivot of motor, it is sunken that the middle part of the rear end of box and relative department with air pipe are equipped with an arc, detachably was equipped with the filter screen between box and arc were sunken.