A temperature control system that employs an incremental PID algorithm based on FPGA technology has been developed to decrease detector noise and dark current while ensure the CMOS detector of the spectrometer obtain more accurate spectrum curve. Considering the current temperature and the control parameters, the appropriate control quantity is calculated to ensure the detector realize the target temperature. Controlling the temperature change rate of the detector is realized through front stage control, effectively solving the problem of overshooting. By adding the anti-integral saturation algorithm and the transition link of the target value, the function of the temperature change rate of the detector is controllable, and the problem of overshoot is solved. Multiple environmental tests conducted on the entire machine indicate that the system can control the temperature of the detector to reach any desired temperature within a specified temperature difference range of 40 °C under the ambient temperature condition in orbit. The sensor temperature has a margin of error of ±0.1 °C. Compared to the conventional analog PID control method, the proposed method offers significant advantages of high sensitivity and strong stability. At a temperature of -10 °C, the noise of the detector is substantially reduced.