Disc filter is called laminated filter which consisted of filter modules. Filter models could work together. The filter unit is a circular reinforced plastic filter disk with grooves or grooves. The grooves in the upper and lower could filter and load residue. Waste water follows from outside. The plates are stacked together in a cell for tight compaction. The rim formed by the groove on the filter plate traps the solid material in water. When backwashing, the water white ring filter plate flows from the inside to the outside, and the dirt left on the filter plate is washed down and discharged through the sewage outlet.