The corrosion of upsnorkel and downsnorkel in 100 t RH furnace was asymmetrical in some domestic steel plants. The corrosion of the inlet side of upsnorkel would be much greater than that of the outlet side of downsnorkel, which could not meet the designed demand of the replacement frequency of the bottom slot and the snorkel, which was designed at 1∶3. Through numerical simulation, the flow field of RH furnace blowing was simulated, and the velocity field distribution of upsnorkel and downsnorkel was obtained. The problem was caused by the big difference in the flow velocity of molten steel between the upsnorkel and the downsnorkel. After adopting the optimization measure such as snorkel swap, the service lives of the bottom slot and the snorkel were up to 333 heats and 111 heats, respectively. The third snorkel could be synchronized offline with the first bottom slot, which absolutely reduced the cost of refractory materials.