The filter mechanism is composed of a filter plate, a filter frame, a filter cloth and a pressed diaphragm. The filter plate is surrounded by a filter cloth on both sides. The base plate of the diaphragm plate is covered with rubber diaphragm on both sides, the outside of the diaphragm is covered with filter cloth, the side plate is the ordinary filter plate. When the material enters each filter chamber from the feed hole on the thrust plate, the solid particle is trapped in the Filter Chamber because its particle size is larger than the pore size of the filter medium (filter cloth) , and the filtrate flows out from the outlet hole under the filter plate. When the cake needs to be squeezed, in addition to the diaphragm press, but also can use Compressed air or steam, from the washing mouth into the air flow to remove the water in the cake, to reduce the moisture content of cake.