A green-light device for driving mice away includes a casing and a control circuit in the casing, wherein the control circuit comprises a power conversion circuit, a voltage regulating integrated circuit (IC), an amplifying circuit, a control knob, an ultrasonic frequency oscillator circuit, a logical-determination circuit and multiple green-light emitting diodes (LED) coupled to and controlled by the logical-determination circuit. The control knob is configured to be switched to lead the control circuit to create an ultrasonic wave or a special light wave such that mice can be cheated or driven away.
