With the development of gypsum industry, there is a large demand for quantity  and high quality of gypsum powder. Therefore, the high level of gypsum powder production technology is required. In the process of gypsum powder production, drying and dewatering is the key link, which is also the most difficult one to control. In order to solve this problem, we develop a new type of drying and dewatering equipment---ebullience calciner, which is produced based on the exploring of the gypsum production filed. Following is the brief introduction of the gypsum production technology and ebullience calciner working principle.