The utility model relates to a novel flange sealing clamp for a hot blast valve, which comprises a clamp body. An injecting threaded hole is arranged at a flange connection gap position of the periphery of the clamp body and connected with an injection valve. The clamp body adopts a three-portion structure. A clamp lug board capable of connecting the three portions is respectively arranged at two ends of each portion, and each two adjacent clamp lug boards are connected through a bolt. The clamp has a reusable function, can conduct secondary complementary injection on portions which are not sealed closely, on the one hand can improve fast leaking stoppage efficiency, and on the other hand can save cost of repeat manufacture of the sealing clamp. Simultaneously, the flange sealing clamp for the hot blast valve is further applied to leakage sealing of other relevant valve flange sealing faces, is not subject to effect of a flange slight staggered joint and eccentricity, can achieve a good effect of pressure sealing, eliminates potential safety hazards of devices, saves overhaul time to the maximum degree, reduces labor intensity, and reduces shut-down loss.