In the field of detection, infrared spectroscopy has been widely used to quantitatively detect components in liquid, solid and gas mixtures . Aiming at the problems of complicated calculation process, background and noise interference, and spectrum overlap from multi components in infrared spectroscopy quantitative detection. On the one hand, a method based on second order derivative spectrum for the original absorption line was used to quantitative detection. The background and noise interference were removed in second order derivative spectrum, and the aliasing absorption peaks were distinguished to a certain extent. In the process of obtaining second order derivative line, Savitzky-Golay filter was used for smoothing filtering the spectrum. The optimal filter parameters were selected according to the spectral line frequency characteristics, which makes up the lack of the standardized methods in filtering parameters selecting. On the other hand, the characteristic absorption windows in term of the absorption distribution of corresponding components were applied to both original absorption line and second order derivative spectrum. The characteristic absorption region of more importance in the concentration calculation was extracted, so as to eliminate the interference of background, noise and other components in the non absorption region. The multi components mixtures of propane, propylene and methylbenzene were used as samples for quantitative detection with both methods mentioned above together with the method using original absorption lines. Then a comparison of the results by different method was analyzed. The experiment results show that the quantitative detection methods by using the second order derivative spectrum and the characteristic absorption window can achieve higher accuracy with relative error less than 5%.