To provide a conveyor housing, a conveyor device and a conveyor dust prevention system that causes less deposition of powder and the like in the bottom of the housing compared to a conventional technique.

The conveyor dust prevention system 100 comprises the conveyor device 10 having the conveyor housing 1 that houses a belt conveyor 11 in which a plurality of pulleys 12, 13 and 17 are arranged inside a conveyor belt V shaped into a band forming a closed loop and which conveys powder N, and that has an air outlet 4 formed above a conveying surface S1 of the conveyor belt V and air inlets 6 and 7 formed below a return surface S2 of the conveyor belt V; a dust collector 20 connected to the air outlet 4 via piping P1; and a blower fan 30 connected to the dust collector 20 via piping P2.