Objective: By quantitatively characterizing the changes of moisture and physical properties, the research aims to provide scientific basis for elucidating the drying mechanism and optimizing the drying process of Moutan Cortex decoction pieces. Methods: The drying characteristic curve was established to study the drying kinetic characteristics of Moutan Cortex decoction pieces. The water phase, distribution, migration and physical properties of Moutan Cortex were studied by LF-NMR/MRI and physical properties analysis technology during drying. Furthermore, HPLC was used to investigate the content changes of paeonol and paeoniflorin which are the indicative components of Moutan Cortex decoction pieces during the drying process. Results: When dried at 55℃, Moutan Cortex decoction pieces had a constant-rate drying period and a falling-rate drying period, which needed to dry for 5 hours. The results of LF-NMR/MRI showed that the water dissipated from outside to inside during the drying process. The water phase changed significantly, and the proportion of bound water increased greatly first and then decreased slightly. After drying for 2 hours, water imaging information of Moutan Cortex could not be detected. With the extension of drying time, all physical properties were increased, and the changes were not obvious within the first 2 hours, but were significant after 2 hours. Within 5 hours of drying, the content of paeoniflorin and paeonol in Moutan Cortex decoction pieces did not change significantly. Conclusion: The combination, including drying kinetics, LF-NMR/MRI and texture properties analysis techniques, can characterize the drying process of Moutan Cortex decoction pieces directly and quantitatively, which provides the theoretical basis for illustrating and optimizing the drying process.