A control circuit of a sensorless motor includes a first coil, a second coil, a first switch circuit, a second switch circuit and an auxiliary switch circuit. The first switch circuit is electrically connected to the first coil and controls a direction of a current flowing through the first coil. The second switch circuit is electrically connected to the second coil and controls a direction of a current flowing through the second coil. The auxiliary switch circuit is electrically connected to and between the first coil and the second coil and controls the directions of the currents flowing through the first coil and the second coil by cooperating with the first switch circuit and the second switch circuit. A control method of a sensorless motor is also disclosed.