The invention provides a nozzle for tire fire extinguishing. The nozzle comprises a nozzle body and a protection cover. The nozzle body is provided with a circular truncated cone with a spray hole and a stepped cylinder longitudinally and sequentially. The protection cover is of a thin-walled structure which is made from a nonmetallic material and equal in the wall thickness. The stepped cylinder longitudinally comprises a large cylinder section, a medium cylinder section and a small cylinder section, the maximum-diameter section is connected with the circular truncated cone, and the minimum-diameter section is located at the tail end of the nozzle body. The stepped cylinder is provided with a mounting thread. A central hole which penetrates through he stepped cylinder and is coaxial with the stepped cylinder is formed in the end face of the bottom of the minimum-diameter section. The protection cover can effectively prevent the spray hole in the nozzle body from being blocked by foreign matter such as slurry, dust and gravel, the interior of the nozzle and a pipeline are kept clean and unobstructed, and reliable operation of the nozzle is ensured; when fire extinguishing agents are sprayed out of the nozzle, the protection cover can be automatically separated from the nozzle body under the action of the fire extinguishing pipeline, other power and extra mechanisms are not needed; and the nozzle is simple in structure, low in cost and high in reliability.