The invention discloses a narrow-gap arcing-based current-limiting air-type DC circuit breaker. The narrow-gap arcing-based current-limiting air-type DC circuit breaker comprises a conductive contactsystem, an arc extinguishing chamber, a rapid repulsion mechanism and a slope insulation pull plate. When a short-circuit fault occurs, the slope insulation pull plate is driven to move by the rapid repulsion mechanism, the breaking of the conductive contact system is achieved, a DC arc which is generated is pushed into a narrow-gap structure, and the arc is rapidly and fully extruded, stretched and cooled; the breaking speed is increased by a symmetric connection rod contact structure, a limitation spring is used for providing enough maintaining force for a contact, and the short-time durability of the circuit breaker is improved; moreover, a repulse metal disc is used as a driving device of the insulation pull plate and the contact to move, the action speed of the circuit breaker is obviously improved, and the breaking time is greatly shortened; and the narrow-gap arcing-speed current-limiting air-type DC circuit breaker is particularly applicable to a low-voltage and large-capacityDC current occasion requiring rapid and reliable breaking.