A direct current circuit breaker, including: n in number circuit breaker modules connected in series, one energy-absorbing and voltage-limiting module connected in parallel to the n in number circuit breaker modules, and a trigger module. The n in number circuit breaker modules each includes a mechanical switch and a commutation branch circuit which are connected in parallel; each commutation branch circuit includes a charging commutation module and a commutation capacitor which are connected in series; the charging commutation module is configured to charge up the commutation capacitor and produce reverse current to cut off the mechanical switch; the one energy-absorbing and voltage-limiting module is configured to absorb energy stored in inductive elements of power systems after a fault current is cut off, so as to limit voltage and protect the mechanical switch, and n is a positive integer greater than or equal to 1.