An in-vehicle automated external defibrillator system and a method of controlling the same, for detecting a state of a driver and applying an electric shock to his or her heart in the event of emergency, are disclosed. The method of controlling the in-vehicle automated external defibrillator system includes determining, by a driver state recognition device, a state of a driver through a state determination device, upon determining that the driver is in a cardiac arrest state, determining, by a heart impulse position controller, two current pads among a plurality of current pads disposed in a seat belt, determining, by a heart impulse intensity controller, current to be applied through the two determined current pads, and applying, by the heart impulse intensity controller, the determined current through the two determined current pads.
