The utility model relates to a nozzle mechanism of a bolt coating machine. The nozzle mechanism comprises a seat body and a nozzle. The rear end and the upper part of the seat body are respectively provided with a gas inlet and a feeding port which correspond to each other in terms of position. The gas inlet is externally communicated with high-pressure gas. A mixing chamber communicated with the nozzle is arranged in the seat body and respectively communicated with the gas inlet and the feeding port. The nozzle mechanism is characterized in that a returning chamber communicated with the mixing chamber is arranged between the nozzle and the seat body; the bottom of the nozzle is provided with a returning port communicated with the returning chamber; a gas duct is arranged between the gas inlet and the mixing chamber; an end part of the nozzle is of a gradually-narrower cone shape; the seat body is connected with the nozzle by a thread; and the seat body is also connected with the nozzle by a clamp. The nozzle mechanism of the bolt coating machine has high productivity and high coating uniformity and can prevent the nozzle from being blocked.