Abstract: High-voltage DC circuit breakers (DCCB) are an effective way to solve the rapid isolation of multi-terminal and DC grid faults. It has developed rapidly worldwide in recent years and has completed prototype development and applications based on different technical routes. Hybrid high-voltage DC circuit breakers have become the mainstream technology route, but its large-scale application in DC grids is still restricted due to the large number of full-controlled devices, low utilization and high cost. This paper proposes a hybrid multi-port DC circuit breaker (MP_DCCB) topology based on the module cascaded technology for the DC grid multiple lines application. Then the operation principle under typical system fault conditions is expounded, and mathematical analysis and design of the core components electrical stresses is completed. Simulation study on the application performance of the proposed topology in the four-terminal DC grid is carried out, and completes the comparative analysis with the existing technology. The research results demonstrate the feasibility and practicability of the proposed multi-port topology, which provides a solution for the technical and economic performance improvement of high-voltage DCCB and promotes the wider application of high-voltage DCCB in DC grids.