The present invention relates to a micro-current stimulator used in an earphone terminal of a portable terminal, and a control method therefor, wherein the micro-current stimulator: is connected to the earphone terminal of the portable terminal having a predetermined application program installed therein is provided with an earphone jack safety control unit, thereby ensuring a stable grounding terminal and power terminal even when groundings are located in different locations according to the types of earphone jack connection terminals and enabled to be stably driven even with a low output current. A method for driving the micro-current stimulator of the present invention comprises: a start-button-on-waiting step of waiting in a portable terminal until a start signal of a start button is received at an operation processing unit of the portable terminal a test signal generating step in which the portable terminal generates, when the start button is turned on, a test signal, and outputs the test signal to either a right acoustic signal terminal or a left acoustic signal terminal of an earphone jack, so as to check whether an electrode patch is attached to a user a first electrode attachment determining step in which the portable terminal determines whether the electrode pad is attached to the user by comparing whether a feedback signal received from a feedback output terminal of the micro-current stimulator is the same as a preset reference range or reference signal an electrode unattachment notifying step by which the portable terminal displays the unattachment of the electrode pad on a screen and returns to the start-button-on-waiting step, if the electrode pad is determined to be unattached in the electrode attachment determining step and an electrode pad driving step of driving the electrode pad by outputting a micro-current in a preset stimulation waveform to the electrode pad, if the electrode pad is determined to be attached since the received feedback signal f
