The invention relates to the field of1 blast furnace wind gap equipment, in particular to a small jacket for blast furnace wind gap. The small jacket comprises a front end and a main body, and is characterized in that the small jacket structure is provided with two independent cavities, namely the front cavity and the back cavity; cooling water is adopted to cool the cavities respectively, wherein the front cavity is cooled by soft water during normal operation, and the back cavity is connected with industrial water for emergency; and when the front cavity is damaged and water leaks, a water feed valve of the front cavity can be shut, and the back cavity can be started, so that the normal operation of the small jacket can still be guaranteed. Compared with the prior art, the small jacket provided by the invention has the benefits that the small jacket adopts the method of double inlets and double outlets; the front cavity is cooled by soft water for normal operation, and the back cavity is connected with industrial water for emergency, so that the overall service life can be prolonged by approximate 3 months; the replacement of the small jacket can increase in operation efficiency during planned damping down period without influencing the production of the blast furnace; and the use value and economic benefit are good.