Abstract: In view of the fact that the sealing ring of the discharge plate at the bottom of Maerz kiln is easy to be damaged in daily production，this paper analyzes the reasons from the surface control of the finished material of the small material bin at the bottom of the kiln，the action control of the hydraulic cylinder of the discharge plate and the quality control of the finished product calcination，etc.，by improving the material level detector of the small material bin at the bottom of the kiln，adjusting the operating speed of the hydraulic cylinder of the discharge plate，optimizing the process control of the kiln，stabilizing the quality of the finished product and prolonging the service life of the sealing ring.

Key words: Maerz kiln, Discharge plate, Sealing ring