A bipolar bidirectional DC converter comprises at least two valve group series (101, 102) and at least six magnetic elements (103), and said valve group series are divided into a Type-I valve group series (102) and a Type-II valve group series (101) each valve group series (101, 102) comprises a high-voltage DC port, a low-voltage DC port and at least three AC ports, and each AC port is connected to a magnetic element (103); and the other ends of the magnetic elements (103), which are connected to all the AC ports in the same valve group series (101, 102), are connected.