YNTSH-ZS series online manual cleaning filter is mainly used in hot water pipe network systems of power plants as an automatic sewage filter. According to the dirty condition of filter screens, a differential pressure on filter screens increases to the set value, and the backwashing mechanism is automatically started and the drain valve is opened, until it drops below the set value; then, the backwashing mechanism and drain valve are automatically closed, while the cleaning cycle and cleaning time and manual cleaning function are also set. The automatic sewage filter is composed of high-quality carbon steel tube, butterfly valve and sewage system; the butterfly valve is turned on when the device is in the filter state, and water flows from the entrance into the filter and is discharged out of the outlet through the cartridge, while impurities are blocked inside the cartridge. After working for some time, however, solid particles are accumulated more and more, the effective filtration area of the cartridge will become increasingly smaller, leading to an increasing pressure drop, when the butterfly valve is closed and the drain valve is opened at the same time. Due to the pressure difference between inside and outside the cartridge, part of the water flows into the backwashing system from the inlet, and the solid particles attached inside the cartridge wall are continuously washed down and are discharged out of the outfall, so that the pressure drop will be restored to its original state, and the filter is put into a normal working condition. When the device is involved in the backwashing course, the entire filtration system can run normally, without need to stop.