Pre-reduction shaft furnace is a typical gas solid countercurrent reactor, in which complex transport phenomenon exists between gas-solid phases. In the present paper, a mathematical model has been developed to simulate the actual pressure field of the shaft furnace, the gas flow field and the distribution of gas flow backwards. The simulation results of the pressure field indicate that the pressure is distributed uniformly at the same height in the furnace. The results of gas flow field indicate that the velocity of gas flow near the side wall is larger than that in the inner part, and a gas dead zone exists at the lower part of the shaft furnace. Comparing the volume of gas flow through the every DRI downcomers, it can be drawn that the gas flow from DRI downcomers near the gas export side is higher than the other side.