Direct-current circuit breaker with air blowing function

The utility model relates to the field of direct current circuit breakers, in particular to a direct current circuit breaker with an air blowing function, which comprises a mounting rack, an operating mechanism, a static contact, a moving contact, an arc extinguish chamber, an arc extending device and an air blowing device, the driving end of the operating mechanism is contacted with the moving contact, and the fixed end of the moving contact is hinged with the mounting rack; an arc extinguishing grating is arranged in the arc extinguishing chamber; the arc extending device is arranged at the inlet of the arc extinguishing chamber and is connected with the static contact; the air blowing device comprises an air cylinder, a piston, a piston pull rod and a driving piece, the air cylinder is connected with the inner wall of the shell, the piston is slidably connected into the air cylinder, one end of the piston pull rod is connected with the piston, and an outlet of the air cylinder faces an inlet of the arc ext