The invention discloses a system and a method for an integral household water network. The system comprises a water inlet joint of a municipal water supply network, wherein the water inlet joint is connected into a home through a controllable electromagnetic main valve, and then is connected with softened water preparation equipment, the output of the softened water preparation equipment is respectively connected with pure water preparation equipment and ultrafiltration water preparation equipment, the output of the pure water preparation equipment is connected with a pure water storage tank, and the output of the ultrafiltration water preparation equipment is connected with an ultrafiltration water storage tank. The method comprises a water usage control method of the pure water storage tank and the ultrafiltration water storage tank, and a preparation method of bathroom water. The system and the method have the advantages that according to different water usage quality requirements of homes, a home owner only requires to change parameters on a touch screen, and then the water with required quality is obtained; the control is convenient, the integral structure is reasonable, and the living quality of people is improved.