Abstract: The air heating technology is applied to the field of environmental simulation to simulate the oxidation of coal when the external environment temperature is different and the loose coal is piled up. The high temperature air heater was developed, and the actual stacking environment of coal was simulated by sending the air heated to different temperatures by high temperature oil bath to the environmental simulation box. The working process and functions of the heater are described in detail, the specific size of the spiral coil used in the heater is calculated, and the heating efficiency of the equipment is determined through practical tests. The results show that the actual coil number is 3 and the length is 2.198 1 m when the vertical spiral coil heat exchanger is selected. The air in the coil is heated by high temperature oil bath. The temperature control accuracy of the heater is ±1 ℃. The actual air heating efficiency is relatively high, and increases with the increase of flow rate.