A hybrid direct current circuit breaker and a power unit. The direct current circuit breaker comprises a commutating branch, a connection/disconnection branch, and an energy absorption branch that are connected in parallel. The connection/disconnection branch comprises several connection/disconnection units that are connected in series, wherein the connection/disconnection unit uses a particular power unit structure. The particular power unit structure comprises at least one forward channel branch and at least one reverse channel branch that are connected in parallel. The forward channel branch and the reverse channel branch each comprise a fully-controlled power device and a diode that are connected in series in a same direction. The conduction direction of the forward channel branch is opposite to that of the reverse channel branch. By connecting a plurality of single channel branches in parallel, the connection/disconnection units of the direct current circuit breaker effectively improve the flexibility an
