The present disclosure relates to a DC/DC conversion system, including a plurality of switch conversion branches, each of the switch conversion branches includes: a primary side circuit, having an input end connected in parallel with an input capacitor; a transformer, having a primary winding coupled to the primary side circuit; and a secondary side circuit, coupled to a secondary winding of the transformer, wherein, input ends of the primary side circuits of the plurality of switch conversion branches are connected in series to form a system input end, output ends of the secondary side circuits of the plurality of switch conversion branches are connected in series to form a system output end, and a filter circuit is connected in parallel with the system output end.