The invention discloses a desulfurization spray gun. The desulfurization spray gun comprises a hose, a spray gun main body, a refractory material layer, a material spraying hole, a rotating device and a fixing device, wherein the hose is used for conveying a desulfurizing agent; a passage for conveying the desulfurizing agent is arranged in the spray gun main body; the upper end of the spray gun main body is connected with the hose; the refractory material layer is formed on the outer surface of a part of the spray gun main body, which is soaked into molten iron; the material spraying hole is formed at the lower part of the refractory material layer and is communicated with the passage; the rotating device is used for ensuring the spray gun main body to rotate back and forth; the fixing device is used for transversely fixing the spray gun main body and allowing the spray gun main body to rotate. According to the invention, the desulfurization spray gun cannot swing in the process of spraying the desulfurizing agent into the molten iron or semisteel and the desulfurizing agent can be uniformly distributed in the molten iron.