The invention discloses a multifunctional high-efficiency water-saving tap, relating to a water-saving tap, which comprises a valve body, a valve core, a hand wheel device and an auxiliary device, wherein the valve core is of a screw plug type and comprises a valve core inner sleeve, a valve core screw plug, a valve core screw rod, a screw rod yoke, a fixed screw cover, a screw rod clamping shoulder, a sealing water line plug, a water line plug connecting rod , a connecting rod through hole, and an clearance water gap; the handle wheel device comprises a hand wheel and a fixed bolt; the auxiliary device comprises a blocking prevention nano filer screen, a water-saving nozzle, and a microfiltration oxygen increaser; and a valve core outer sleeve is located in the middle of the valve body, the valve core inner sleeve is arranged in the valve core outer sleeve, the valve core screw plug is located in the valve core inner sleeve and can move up and down in the valve core inner sleeve, the water line plug connecting rod is connected with the bottom of the valve core screw plug and the top of the sealing water line plug, and one end of the valve core screw rod is connected with the handle wheel and the other end of the valve core screw plug and used for switching the sealing water line plug through a rotary hand wheel. The multifunctional high-efficiency water-saving tap has the characteristics of superior technical performance, constant pressure and current stabilization, microfiltration for dirt cleaning, favorable water quality, high-efficiency water saving, wide adaptation, firmness, durability, and advanced comprehensive cost performance.