The invention discloses a precise liquid filtering apparatus. The apparatus comprises a rotatable filter cylinder device, the rotatable filter cylinder device is provided with an ultrasonic wave or air explosion cleaning device, the filter cylinder device is connected with a liquid inlet tube, a liquid outlet tube and a waste discharging tube, the filter cylinder device communicates with a filter stock solution through the liquid inlet tube, the liquid inlet tube is provided with a circulating pump, the water outlet tube is provided with a vacuum pump, a filtered filtrate is pumped out by the vacuum pump, and the waste discharge tube communicates with the filter stock solution. The apparatus adopts a nuclear porous membrane or an effective compound of the nuclear porous membrane and other filter materials as a filter material reserves the filtration characteristics of a traditional filter material and the fine filtration effect of the nuclear porous membrane, and the apparatus adopting a cross flow filtration manner keeps pollutants on the surface of the filter membrane at a small level, alleviates the obstruction of filter pores, improves the filtering efficiency and prolongs the service life of the filter membrane.