As the protection equipment of the DC distribution network, the DC circuit breaker is of great significance to the safe and stable operation of the DC distribution network. A topology design scheme for cascaded modular solid-state DC circuit breakers suitable for DC distribution networks is proposed. The topology of the proposed scheme reduces the pressure on the arrester to absorb energy and accelerates the current breaking speed by introducing a grounding diversion diode group; the transfer branch adopts a cascaded modular structure to solve the problem of dynamic voltage equalization of a large number of IGBTs connected in series. The DC circuit breaker model of 10 kV DC distribution network is designed based on the proposed topology, which is verified in PSCAD/EMTDC, and analyzed and compared with other literatures. The results indicate that the maximum breaking current of the solid-state DC circuit breaker based on the proposed scheme is 5 kA, the fastest time to remove the fault current is 2.96 ms, and the time for the arrester to absorb energy is 1.24 ms. The energy absorbed is halved compared with other schemes, which is in consistent with DC circuit breaker design requirements. The feasibility of the scheme is verified by the simulation results in this paper.