The invention discloses a building hotel household centralized purification and energy-saving water supply system. The system comprises a water supply end, a primary filtering end, a pressurizing end,a core filtering end, a recovery end, an automatic control end, a water use end and a cleaning end; and the water supply end is connected with the primary filtering end, the primary filtering end isconnected with the pressurizing end, the automatic control end is electrically connected with the primary filtering end and the pressurizing end, the pressurizing end is connected with the core filtering end, and the core filtering end is connected with the water end, the recovery end and the cleaning end. According to the system, building water supplying is effectively stable, the situation thatpeople cannot normally use a water source is reduced, and the water supply facility is perfect; meanwhile, the water source is purified and saved, the waste of water resources is reduced, the proportion of the purified direct drinking water to the concentrated water is two to one, the water production efficiency is greatly improved, the concentrated water is fully utilized, the situation that concentrated water flows directly into a sewer is avoided, waste is reduced, and resources are saved.