Abstract: Drying is one of the important technological steps in the production of traditional Chinese medicine pills. The key to ensure the quality of pills lies on the reasonable control of drying technology. The diffusion and distribution of water in pill are affected by the external conditions during drying process, and the mechanical properties of pill components are also affected by the external conditions. Pill crack is a typical problem caused by the change of mechanical properties of pill components in drying process, which also affects pill appearance, disintegration and melting time. At present, there is no theory to explain the formation process of pill drying crack, which leads to the absence of guiding basis for the high-quality production of pill drying. In this paper, from the perspective of component properties and forming process of pills, and with the aid of glass transition theory, the formation reason of cracked pills during drying is analyzed, and the new technology of glass transition temperature measurement and process control drying method are analyzed, in order to provide reference for solving the problem of dried cracked pills of traditional Chinese medicine pills.