The disc filter adopts modularization design, which can be used in various combinations according to the filtering unit to meet the actual needs of different application occasions. The backwashing control operation is simple, and it can be controlled according to the pressure difference and time. It has the characteristics of high-efficiency backwashing, fully automatic continuous operation, low self-consumption, small footprint, and reliable operation. The backwashing process of the filter system alternates, and the working and backwashing states are automatically switched, which can ensure continuous water output and small system pressure loss. Therefore, the technical advantages are very obvious.