The invention discloses a high-input power factor control method for a single-phase to three-phase inverter motor drive system. A motor has a relatively high input power factor no matter in a light load operation condition or a rated load operation condition by controlling a quadrature-direct axis reference current. Compared with a control method for input current feedback of an inverter and output power feedback of the inverter, the direct control method for a direct input power associated with AC input voltage and current lowers the complexity of system control and improves the accuracy and the dynamic response of the system control; fewer sensors are utilized; and the cost of the system is reduced. Meanwhile, the adverse effects on the operating performance, such as a torque and a rotating speed, of the motor caused by a relatively low input power are avoided by a low-power limit unit.