Tunable diode-laser absorption spectroscopy(TDLAS) has a good prospect of application, such as environmental monitoring, industrial process detection, due to its high resolution, high sensitivity and rapid measurement. But the wavelength of laser shifts with the change of ambient temperature when the system is working continuously for a long period of time. Aim at this problem, the wavelength variation with the change of temperature and the quantitative impact on spectral processing is studied. In order to eliminate the shift of wavelength, ADμC841 is used for temperature compensation, this system can re-set the temperature of the laser according to the ambient temperature to lock the laser spectrum. The experiment in temperature-controlled device at the temperature of 20 ℃～60 ℃ shows that the shift of laser wavelength is about 4.1 pm.