The invention discloses a three-phase active power factor rectification method for realizing the three-phase power factor correction and the three-phase input current harmonics reduction, which comprises the following steps: obtaining an input current average value of two-phase in the n-th PWM period; regulating the obtained control parameter via a PI based on the output voltage; calculating the equivalent rated load resistance on each phase AC side, the equivalent rated load resistance on each phase AC side in the rated power and the duty cycles of three bidirectional switches in the next PWM control period, finally outputting three bidirectional switch duty cycle control signals to control three corresponding bidirectional switches by a DSP control system at the beginning of the next PWM control period. The invention adopts a DSP (Digital Signal Processor) as the control core to realize the three-phase active power factor rectification without an input voltage sensor approaching to the unity power factor.