An air conditioner and a startup control method and system for an outdoor fan of the air conditioner. While in a process of charging a bootstrap capacitor in an actuator of a motor of the outdoor fan, an initial rotation state of the motor is detected in real time, and, when charging of the bootstrap capacitor is completed, startup of the motor is correspondingly controlled on the basis of the detected initial rotation state. This allows real time initial startup work state to be acquired when charging of the bootstrap capacitor is completed, thus allowing the motor to be started smoothly, increasing the success rate in starting the motor, and solving the problem of low success rate in starting the motor of an outdoor fan.