This study was set to learn about the original processing methods of PAEONIAE RADIX ALBA(PRA) and PAEONIAE RADIX RUBRA(PRR) in the Part I of Chinese Pharmacopoeia(2020 version). We used color difference meters and high performance liquid chromatography(HPLC) methods to charaterize the appearance, chromatic value of section and content of paeoniflorin after processing the fresh roots. Then grey correlation analysis(GCA) was applied to optimize different original processing conditions. The results showed that the content of paeoniflorin was significantly affected by peeling, cold or hot water boiling, boiling time and drying method, and boiling treatment also had partly influence the sectional color and chromatic value. The GCA analysis further showed that the correlation degree between the content of paeoniflorin and the drying method was the highest(correlation coefficient was 0.834), followed by the boiling time, and the value of correlation coefficient between the section chromatic value and boiling time was 0.746. Thus, our study found that the optimal processing method should prepare boiling 1-8 min for the fresh root, peeling and then drying at 60 ℃ for PRA, and drying at 60 ℃ for PRR.