The present study aimed to design a temperature control system and a new control scheme to precisely control the temperature of the fast steering mirror. The temperature control system considered the single chip microcomputer as the core control element, and the thermoelectric cooler as the executive element. The system used a nonlinear proportional-integral-derivative active disturbance rejection control algorithm based on wavelet denoising to control the temperature. The control parameters were tuned through particle swarm optimization algorithm based on Sigmoid personalized inertia weight. The simulation and experimental results show the effectiveness of the control scheme in suppressing the startup temperature drift of the fast reflector. It is found that the temperature control accuracy reaches ±0.02 ℃ in the temperature control range of 15 ℃-28 ℃, which can be stabilized at the preset temperature within 142 s. In addition, the results show that the designed temperature control system has fast response speed, high-control accuracy, strong robustness, and good performance of application value.