Airborne lidar is an important means to achieve long-range accurate atmospheric monitoring. Its laser wavelength is consistent with the absorption spectrum of most atmospheric pollutants and chemical substances, which makes it an important laser source for airborne lidar. However, it is difficult to design a temperature control system for airborne CO₂ lasers to work in the -40 °C-55 °C temperature range under the controlled volume and weight conditions. In this paper, we propose a temperature closed-loop control method, in which the laser characteristic and environment temperature are used as input, and a thermo electric cooler and forced air cooling are combined. According to the structure and heat transfer characteristics of the laser, the thermo-electric cooler and the level of forced air cooling, the finite element model of temperature control method is established to optimize the temperature control performance of the laser. In a high temperature environment of 55 °C, the temperature of the laser is controlled at 40 °C after the temperature control system operates for 25 min. In a low temperature environment of -40 °C, the laser temperature is controlled at 25 °C after the temperature control system operates for 20 minutes, which meets the normal working requirements of the laser. According to the laser and the established temperature control method, the experimental research on the working ability of the laser in high and low temperature environment is carried out, the temperature data of the laser in the experimental process is collected, and the laser output power is measured under high and low temperature conditions. The experimental results show that the experimental measured temperature data is consistent with the finite element simulation results and the error between them is less than 10%. The laser using the proposed temperature control method can work steadily, and the output power of the laser is consistent with that of the laser at room temperature.