To overcome the disadvantages of the previous air reactor in our in situ gasification chemical looping combustion (iG-CLC) system, a novel multistage tower-type air reactor was first proposed in this work. It was mainly comprised of a tower-type moving bed, three gas distributors, and three gas dischargers. Feasibility of the multistage design and gas flow paths was investigated in detail in the experimental system of the air reactor. The results show that, in comparison to the previous single-stage air reactor, the carrying capacity of the gas flow was obviously enhanced by the multistage design. Under the involved single-inlet operating conditions, the gas leakage proportion increased with an increase in the inlet gas flow rate, which could be caused by the tower-type structure or increasing penetration power of the gas. The gas bypassing from the first and third stages to the second stage could be effectively minimized by increasing the second-stage outlet pressure, while the gas leakage from the second stage to the third stage could be controlled by regulating the third-stage outlet pressure. The gas leakage proportions between different stages under the multi-inlet conditions were smaller than those under the single-inlet conditions. Under the involved multi-inlet condition, increasing the inlet gas flow rate at one stage could not only influence the gas distribution at this stage but also affect the gas flow paths at the other two stages. Further, to minimize the gas leakage between different stages and enable favorable operation conditions, it could be effective to first regulate the third-stage outlet pressure and then adjust the second-stage outlet pressure.