Abstract: The smog chamber simulation experiment is a method for studying the mechanisms of atmospheric pollution and formulating effective pollution control strategies. The Realizable k-ε model in the computational fluid dynamics (CFD) software Fluent was used to simulate the heat transfer process in the plateau indoor smog chamber experimental system and the turbulent mixing process under different fan speeds. The internal temperature distribution of the smog chamber experimental system and the material concentration distribution in the reactor were obtained. The uniformity of the overall spatial temperature distribution and the degree of material mixing in the reactor were analyzed, and the temperature simulation results were compared with the experimental results. The results showed that according to the Realizable k-ε model, the flow field characteristics, temperature field distribution and material mixing degree in the reactor of the smog chamber experimental system were studied by simulation, and the performance of the smog chamber experimental system was verified; through field experiments, the maximum error between the measured value and the simulated value was not more than 8.59%. The temperature field distribution in the chamber of the smog chamber experimental system was relatively uniform, and the temperature in the reactor was more difficult to reach a temperature-stable state than that in the chamber. The actual temperature was distributed in a gradient, and the difference between the temperature value at the center and the set target temperature was less than ±1 ℃. The overall material mixing degree in the internal space of the reactor was good, but the mixing unevenness and material aggregation appeared at the edges, vertices and wall positions, respectively. The fan speed had little effect on the mixing time, and too high speed conditions would increase the wall loss of the material in the reactor.