The invention discloses a high-voltage direct-current circuit breaker based on a rapid repulsion force mechanism and an insulating transformer. The circuit breaker topologically comprises a current conversion branch circuit, a main circuit breaker branch circuit, a rapid switching energy supply unit, a main loop electric reactor unit and a main loop isolation switching unit. The current conversion branch circuit is an LC oscillation branch circuit. The main circuit breaker branch circuit is formed by connecting an adjustable electric reactor and a plurality of rapid switching energy absorption voltage-sharing modules in series. Each rapid switching energy absorption voltage-sharing module is formed by connecting a rapid switch, a lightning arrester and an RC voltage-sharing branch circuit in parallel. The rapid switching energy supply unit ensures rapidity and cooperativity of actions of the rapid switches. The main loop electric reactor unit is used for reducing a fault current ascending rate. The main loop isolation switching unit is used for protecting internal components after the circuit breaker conducts breaking successfully. According to the high-voltage direct-current circuit breaker, on the basis of the rapid repulsion force mechanism and the insulating transformer, the breaking speed is high, the fault current is prevented from ascending to the larger amplitude, the voltage level borne by the circuit breaker is high, breaking reliability is high, the structure is simple, and the manufacturing cost is low.