In the actual test，it is found that the leaching rate of 31 batches of Dangshen（Codonopsis pilosula）from different origins is different，with the lowest and highest differences of 20.869%. Therefore，even genuine Chinese medicine will have different effects depending on the place of origin. The appearance of these 31 batches of Dangshen（Codonopsis pilosula）is very similar，and it is impossible to distinguish them by trait identification. Because the 31 batches of Dangshen（Codonopsis pilosula）are all genuine and their main components are the same，they cannot be distinguished by microscopic identification and thin layer identification. In the past，the methods of judging the origin of traditional Chinese medicines，such as liquid chromatography，gas chromatography and polymerase chain reaction，were accurate but required professionals to test for hours or even days. Therefore，this paper took Dangshen（Codonopsis pilosula）as an example to study a method to quickly identify the origin of traditional Chinese medicine based on fourier transform infrared spectroscopy technology（FT-IR）.

Ten batches of Dangshen（Codonopsis pilosula）from different origins were randomly selected and infrared spectrum data was collected separately. Firstly，the similarity of the infrared spectra of Dangshen（Codonopsis pilosula）of different origins was calculated，and the similarity heat map was drawn for preliminary analysis. Five different methods were used to preprocess the original infrared spectrum. The partial least squares（PLS1）model was established and the optimal processing method was selected and the cluster analysis was carried on the selected optimal group. The continuous projection algorithm was used to select the optimal wavelength for the optimal processing method group，establishing a multispectral model and calculating the regression equation for identifying the production location. Finally，the discriminant performance of the regression equation was verified by using the confusion matrix.

The optimal processing method for the full-spectrum model was normalization（NOR）. The spectral data of 10 batches of Dangshen（Codonopsis pilosula）from different origins after NOR treatment can be completely clustered into10 categories by cluster analysis，and samples from the same origin were all clustered in the same category. The value of R2 p of the full spectrum model group was0.980 0，the corresponding RMSEPwas 0.406 7%，and the value of R2 p of the multispectral model established by the 13 optimal wavelengths selected by SPA was 0.990 6 and RMSEPwas0.280 4%. The prediction performance of the multispectral model was better than that of the full-spectrum model，and the variables that needed to be input were greatly reduced，saving time and effort，and the accuracy was high. The regression equation of origin discrimination calculated based on the multispectral model was verified by the confusion matrix，and its sensitivity and specificity were more than 97%，so it is believed that the regression equation can quickly and accurately determine the origin of Dangshen（Codonopsis pilosula）.

The FTIR method of determining the origin of traditional Chinese medicines studied by taking Dangshen（Codonopsis pilosula）as an example is fast and effective，which provides ideas for the research on the origin of other traditional Chinese medicines and provides a theoretical basis for the development of rapid inspection equipment for traditional Chinese medicines in the future.