Water purifier and matching ultrafiltration membrane unit thereof

The present invention discloses a water purifier. The purifier comprises: an inlet pipe, a solenoid valve one, a pressure storage tank, a reverse osmosis membrane filtration group, a booster pump, an ultrafiltration membrane filtration group, a solenoid valve three, and a flushing pipeline, wherein the inlet pipe is connected to a suction mouth of the ultrafiltration membrane filtration group, the solenoid valve three is connected to an outfall of the ultrafiltration membrane filtration group, the booster pump is connected to a draining outlet of the ultrafiltration membrane filtration group, the reverse osmosis membrane filtration group is connected to the booster pump and the pressure storage tank, an inlet end of the flushing pipeline communicates to a pipeline between the reverse osmosis membrane filtration group and the pressure storage tank, the outlet end of the flushing pipeline communicates to a pipeline between the draining outlet of the ultrafiltration membrane filtration group and the booster pump, the solenoid valve one is disposed on the flushing pipeline, and a pipeline between the inlet pipe and the ultrafiltration membrane filtration group is provided with a pressure valve or a control valve. The invention further discloses a matching ultrafiltration membrane unit of the water purifier. The application of the invention facilitate the use of clean water to back flush the ultrafiltration membrane filtration group, so that a flushing quality is ensured, a flushing effect is enhanced, replacement frequency of membrane bundles is reduced, and a cost is saved.