The invention discloses an MMC dual-loop circulating current restraining method based on a quasi proportional resonant adjustor. The method comprises the steps that a three-phase MMC basic mathematical model is obtained through a three-phase MMC topological structure and a single-phase equivalent circuit on the basis of the Kirchhoff's law; a more precise phase unit instantaneous energy expressionis obtained; an instruction value of an internal unbalanced current direct component is obtained; dual-loop circulating current restraining based on the quasi proportional resonant (PR) adjustor is achieved; the MMC internal unbalanced current circulating current component and direct current component are controlled separately, and internal circulating current signals are added to feedback signals of a direct current component control loop; according to given adjustor parameter setting principles, the controller closed loop transfer function zero pole position can be reset, so that the controller damping is increased, and the system stability is improved.