The trap detector is the core component of solar spectral irradiance instrument, but its response rate changes with temperature. In order to ensure the long-term high-precision observations of solar spectral irradiance in the large temperature range field, the temperature of trap detector should be controlled automatically. The method using semiconductor thermoelectric cooler(TEC) to control temperature was presented, and two temperature control circuit based on DSP and the ADN8830 were designed to drive TEC. In the method based on DSP, the digital temperature sensor DS18B20 was used to obtain the temperature, and switch-PID algorithm was used to generate control signals to drive the TEC. The thermistor was used as the sensor, and the temperature was controlled by internal integrated algorithm in the method based on ADN8830. The experiments on the effect of the two circuits show that, the method based on ADN8830 was simple and efficient compared with the method based on DSP, which can control the temperature of the trap detector fast and effectively in the range from －10 ℃ to 40 ℃, and the temperature was stabilized within the range of 25 ± 0.12℃.