The invention discloses a control method of a motor train unit rectifier based on a two-step predictive current controller. The control method comprises the following steps that 1, a current prediction model of the motor train unit rectifier is constructed; 2, a current prediction model under an alpha-beta static orthogonal coordinate system is constructed; 3, two-step predictive time-delay compensation is conducted according to the current prediction models obtained in the step 1 and the step 2 to obtain two-step predictive current vectors; 4, two-step predictive values of currents under a d-q rotating coordinate system are obtained according to the current vectors obtained in the step 3; 5, the two-step predictive values, obtained in the step 4, of the currents are calculated by adopting a quality function to obtain quality function values, the minimum value in the quality function values is selected, a control voltage vector corresponding to the minimum quality function value is obtained, and a corresponding control impulse is directly output in the next sampling period. The control method has the advantages that the quick dynamic response characteristics and the harmonic suppression effect are high, total harmonic distortion is low, small current distortion is generated, and the dynamic response speed is high.