Filter work, the water to be filtered by the water inlet, flowing through the filter, through the outlet to enter the user to the pipeline process cycle, the water particles in acrobatics is trapped inside the filter. So constant circulation, trapped particles more and more, filtration speed more slowly, and imports of sewage continue to enter, the filter will become smaller, resulting in the inlet and export between the pressure difference, when the magnanimity to reach the set value, the differential pressure transmitter transmits the electrical signal to the controller, the control system startup drive motor drives the shaft rotation through the drive assembly, while the sewage outlet is opened, discharged by the sewage outlet, when the filter is cleaned, the pressure difference drops to the minimum value, the system returns to the initial filter, the system is functioning normally. The filter consists of a shell, a plurality of filter elements, a backwash mechanism, and a differential pressure controller. The inner cavity of the shell is divided into the upper and lower two cavities, the upper cavity is equipped with multiple filter cores, so that the filter space is fully reduced, the volume of the filter is significantly decreased, and the backwash sucker is installed in the lower cavity. When working, the turbidity liquid enters the filter cavity through the entrance and enters the inner cavity of the cartridge by the barrier hole. Impurities that are larger than the gaps in the filter core are retained, and the net solution reaches the upper cavity through the cracks, and finally sends out from the outlet. The filter adopts high-strength wedge-shaped filter, which is automatically cleaned by pressure difference control and timing control. When the accumulation of impurities in the filter on the surface of the filter causes import and export pressure difference increase to the set value, or the timer reaches the preset time, the electric control box signals, driving the backwash mechanism. When the backwash suction chuck and the filter inlet are right, the sewage valve opens, at this time the system pressure drainage, sucker and the inside of the filter element appears a relative pressure below the filter element outside the pressure of the negative zone, forcing part of the net circulating water from the outside of the filter element into the inside of the filter, adsorbed on the wall of impurities particles into the Shan plate and discharged from the sewage valve Specially designed filter makes the injection effect inside the filter element, and any impurities will be washed away from the smooth inner wall. When the filter import and export pressure return to normal or timer set time to end, the whole process, the material is not cut off, wash water consumption less, achieve continuous, automated production. The filter is widely used in metallurgy, chemical industry, petroleum, papermaking, medicine, food, mining, electricity, urban water supply field. such as industrial wastewater, circulating water filtration, emulsion regeneration, waste oil filtration treatment, metallurgical industry continuous casting water system, blast furnace water system, hot-rolled high-pressure water descaling system. is an advanced, efficient and easy to operate automatic filtration device.