The invention provides a method and an apparatus for suppressing power annular current of an electromagnetic looped network. The method comprises the steps of calculating the opening voltage of the electromagnetic looped network; obtaining additional control signals of a first inverter and a second inverter and obtaining extinction angle modulation signals of the first inverter and the second inverter; and calculating trigger angles of the first inverter and the second inverter, and determining the output power of the first inverter and the second inverter. Based on the rapidly-adjustable characteristic of convertor station power, a first inversion station and a second inversion station of a direct current power transmission system are subjected to extinction angle modulation separately, so that reactive annular current in the high-voltage and low-voltage electromagnetic looped network can be suppressed dynamically, and real-time changes of an alternating current system can be responded; and based on a direct current hierarchy access type characteristic, a coordination controller is designed, so that influence of mutual coupling of active power and reactive power of the inversion stations in changing the reactive power output can be relieved.