In order to study the heat transfer performance of side nozzle pulse engine, the fluid-solid heat transfer numerical calculation of the engine was carried out by using fluid calculation software, and the transient heat transfer during engine operation was analyzed. The numerical results were in good agreement with the experimental results, which verified the accuracy of numerical method. The results showed that temperature field structures with different material base were basically the same, and due to the thermophysical properties of materials, the temperature gradient of the wall would exist some differences. The vortex flow of gas was the main cause of the high temperature and ablation of the inner wall. The metal oxide particles produced by ablation would intensify the erosion effect of gas, and aluminum base should have thermal protection parts.