The bottom of disctype porcelain is usually grinded by hand.It is low efficiency and easy to hurt the hand. A new type of bottom grinding device for disctype porcelain was put forward. Porcelain could be automatically fed, automatically grinded, automatically quitted. The lifting mechanism was used to realize grinding height adjustment, so it can be adapted to the different height grinding of disc type porcelain. A threedimensional model of key parts for lifting mechanism was established. Contact stress on the gear meshing was analyzed by using ANSYS software.The internal shell was designed and optimized. The prototype runs well in practical work. The desired effect is achieved.