To elucidate the control efficacy of heat treatment on two major important pest insects Sitophilus oryzae and S. zeamais, this paper was made to kill the pests at different spatial positions by heating the ambient air with a heater using two air intake methods, namely the upper and lower ones. In a simulated experimental space, a heater was set up and treated with three heating powers of 1000W, 2000W, and 3000W for 10 to 60 minutes respectively. After the treatment, the mortality rates of S. oryzae and S. zeamais placed at different spatial positions were analyzed. The research results indicate that the mortality rates of the two coleopteran pests were positively correlated with both power and heating time. The increase in power and the extension of heating time both enhance the mortality rate of pests. Different air supply methods affect the killing effect of pests at different positions. The downward air supply method is beneficial for killing pests in the upper layer of the space. When the power is 3000W and the heating time is 50 minutes, all the pests in the middle and upper layers die, but no pests die in the lower layer. The upward air supply method is conducive to killing pests in the entire space. When the power is 3000W and the heating time is 60 minutes, the mortality rate of pests in the environment can reach 100%. In conclusion, the high-temperature environment generated by local heat treatment has a significant control effect on two species of lepidopteran pests. Therefore, it has a promising application prospect in food and grain processing facilities.