Alumina ceramic dry pressing technology is limited to objects with simple shapes and inner wall thickness exceeding 1mm, and the ratio of length to diameter is not greater than 4: 1. The molding method is uniaxial or bidirectional. There are two types of presses: hydraulic and mechanical. They can be semi-automatic or fully automatic. The maximum pressure of the press is 200Mpa. The output can reach 15-50 pieces per minute. Because the stroke pressure of the hydraulic press is uniform, the height of the pressed parts is different when there is a difference in the powder filling.