A three-phase rectification module, the system thereof and harmonic suppression method are provided. The module includes a LCL filter unit, a three-phase uni-directional rectification unit coupled to the LCL filter unit, and a rectifier control unit for controlling power factor of three-phase AC power source and DC output voltage of the three-phase uni-directional rectification unit. A commutation diode is serially connected on the bridge-arm of each set of uni-directional rectification branch which is included in the three-phase uni-directional rectification unit, making it function as current uni-direction. Herein, the power factor of the three-phase AC power source is matched with the parameters of the LCL filter unit, such that the absolute value of the phase difference between AC input voltage and current of the three-phase uni-directional rectification unit is close or equal to a preset threshold.