A brushless motor control device according to the present invention drives a brushless motor including a stator having coils of three phases U, V, and W and a neutral line, and a sub coil provided in any one phase of the phases U, V, and W, for detecting a voltage induced in the coil of the one phase, and the brushless motor control device carries out a conduction control function, for the respective phase coils of the brushless motor, that performs a 120° conduction when a rotation speed of the brushless motor is lower than or equal to a predetermined rotation speed, and that performs a 180° conduction when the rotation speed is higher than or equal to the predetermined rotation speed, and the brushless motor control device includes a motor control unit that controls the brushless motor based on information of the rotor stop position when activating the brushless motor, controls the brushless motor based on the first rotor position information when in the 120° conduction, and controls the brushless motor based on the second rotor position information when in the 180° conduction.