A wireless hair straightener according to an embodiment of the present invention includes a battery charged by an external power supply, a first switch, a first heating resistor, and a second heating resistor which are sequentially connected in series between one end of the external power supply and a ground, a second switch having one end connected to a connection point between the first switch and the first heating resistor and the other end connected to the ground, a third switch having one end connected to a connection point between the first heating resistor and the second heating resistor and the other end connected to one end of the battery, and a control unit that controls on and off operations of the first switch, the second switch, and the third switch, in which the other end of the battery is connected to the ground, and the other end of the external power supply is connected to the ground.