According to the evanescent wave absorption theory, a cavity ring-down spectroscopy detection system which is immune to temperature perturbation is presented. Study has been done to explore the integration of carbon nanotubes and optical fiber apparatus. The physical absorption and desorption characteristic of carbon nanotubes is utilized to realize the measurement of gas or volatile organic solvent (VOS). When fiber cladding is partially removed, the evanescent wave theory is utilized to select the appropriate diameter of fiber cladding, thus the system is sensitive to ambient refractive index and loss can be controlled. A pulsed laser beam with width of 2.5 ns according to the nonlinear polarization dependent mode locking technique is introduced into the ring-down system, and hence, our principle is validated by the highly-sensitive temperature-insensitive measurement of evanescent wave absorption loss.