Abstract: An electronic water flow control device, which includes a mini-scale electrical generator which changes the mechanical energy from water flow into electrical energy for storage in a battery and for further use in driving a motor, by means of the control of a control circuit, to carry a piston rod to move forward or backward through the operation of a speed reducing gear set, so as to push a ball valve away from a water inlet for the passing therethrough of water flow or permit such a ball valve to block up the water inlet.