Abstract: Dynamic photo-thermal-mechanical response of the micro-cantilever with CNTs absorption layer illuminated by an intensity modulated infrared laser source is investigated. The one dimensional state equations of time-dependent temperature and deflection are established to analyze the dynamic characteristics. The CNTs microcantilever was fabricated using the methods of the vacuum filtration and MEMS processing. The DFB laser with the wavelength of 1392nm was employed as the excitation source and the oscillatory properties are worked out. Experimental results indicate that amplitude decreases as the laser pulse frequency increases but it will increase as the laser output power declines with the maximal cut-off frequency of 173Hz, and at last by use of the CNTs microcantilever as the photo-thermal sensor the photo-thermal spectral signal is produced.