The utility model discloses a preparing and controlling system of pure tap water. The preparing and control system comprises a microcontroller module, a water pumping and collecting device, a water supply pipeline and a purification device; the water pumping and collecting device comprises a water pump, a water collecting tank and water level sensors; the two water level sensors are installed at the top and below the side wall of the water collecting tank respectively, and water level signals of the two water level sensors go through a photocoupling pipe to be transmitted to an input/output port of a microcontroller through cables; the microcontroller module controls movements of a relay connected with the water pump according to water level information induced by the water level sensor so as to control the water pump to pump underground water in a well; and the water collecting tank is connected with a water supply terminal through the water supply pipeline, and the purification device is arranged on the water supply pipeline. The preparing and controlling system of the pure tap water is low in costs, low in complexity, high in efficiency and capable of achieving standardization and informatization of drinking water in villages and well solving the problem that people in remote areas drink water difficultly and unreasonably.