The invention discloses a sustainable water pumping device capable of automatically adjusting the size of a water inlet. The sustainable water pumping device capable of automatically adjusting the size of the water inlet structurally comprises a pump body, a water outlet, the water inlet and an adjusting device, wherein the pump body is respectively provided with the water outlet and the water inlet; the adjusting device is arranged on the water inlet and consists of a shell body, an air bag, a ball body, a roller set, a pull rope, a hinge seat, a shielding plate and a resetting mechanism; theshell body is arranged on the bottom of the water inlet; the hinge seat is connected to the side face of the water inlet; the hinge seat is provided with the shielding plate; the shielding plate is movably connected with the hinge seat through the resetting mechanism; the shielding plate is connected with the pull rope; the pull rope penetrates through the roller set to be connected with the ballbody; and the ball body is wrapped in the air bag. The sustainable water pumping device capable of automatically adjusting the size of the water inlet has the beneficial effects that the size of thewater inlet can be automatically adjusted through the height of the liquid level, so that the suction distance is increased, liquid extraction failure is prevented, and the extraction work can be continuously carried out; and the corresponding shielding speed can be adjusted according to the difference of the viscosity of the liquid through the adjustment of the pull rope on the shielding plate, and the use is more convenient and rapid.