As a fast, non-destructive analysis method, Fourier transform (FT) near-infrared (NIR) spectroscopy is very suitable and
effective for online quality analysis of traditional Chinese medicine (TCM) manufacturing process. In this thesis, the
theoretics of FT-NIRS was analyzed and an FT-NIR spectrometer with 4 cm<sup>-1</sup> resolution in the 12500-5000 cm<sup>-1</sup>
frequency range was designed. The spectrometer was based on a Michelson interferometer with Bromine tungsten lamp
as the NIR light source and InGaAs detector to collect the interference signal. Each element was designed and chosen to
provide maximum sensitivity in the NIR spectral region. A fiber-optic flow cell system was used to realize online
analysis of traditional Chinese medicine. The performance of the spectrometer was evaluated and the feasibility of using
FT-NIR spectrometer to get absorption spectra of traditional Chinese medicine was demonstrated.