The operating principle of the inorganic ceramic membrane is “internal pressure cross-flow filtration” mode, that is, the fluid enters through pump acceleration and pressure rise into the membrane element via multiple channels. Driven by the pressure, water and micromolecule dissolved component forms the penetrating fluid (or called the filtrate) through the membrane, some macromolecule components such as suspended solids, grease, etc. are retained by the membrane to form the concentrated fluid (or called the trapped fluid), and discharged from another end. Because the fluid flows on the surface of the microporous membrane at high speed, it is not easy to form the thick filter cake, with small filtration resistance, so it can maintain stable filtration flux in the long time. Because the microporous membrane aperture is tiny, compared with the separation of the conventional centrifuge and the filter type of the plate-and-frame filter press, the membrane filtrate has the higher light transmittance and the fewer impurity content.