The invention relates to a through-flow cavity type blast-furnace tuyere with double flow passages, which belongs to the technical field of blast-furnace fittings. The blast-furnace tuyere has a structural form of integrating through-flow type and cavity type, the front part of the blast-furnace tuyere has a through-flow type structure, the rear part of the blast-furnace tuyere has a cavity type structure, both the through-flow part and the cavity part are provided with a set of independent water inlet and water outlet, both the tuyeres at the through-flow part and the cavity part are provided with a cooling chamber, and the water inlets and the water outlets of the tuyeres on the through-flow part and the cavity part are communicated with the cooling chambers. The through-flow cavity type blast-furnace tuyere with the double flow passages has the advantages that: because the front part of the blast-furnace tuyere has the through-flow type structure, the flow speed of the cooling water is high and the cooling strength is large, and the front part is not easy to burn; once the front part is burnt, the water inlet and the water outlet on the front part of the tuyere can be closed; and because the cavity part on the rear part of the tuyere is provided with the independent water inlet and outlet, the blast furnace can continuously perform production and avoid blowing down for replacement due to the damage of the tuyere.