The invention provides a three-terminal star-shaped interconnected direct-current distribution network topology system. The system comprises three alternating-current distribution systems, three direct-current bus-bars and a star-shaped direct-current circuit breaker group; the star-shaped direct-current circuit breaker group comprises three direct-current circuit breakers connected to form a Y-shaped structure; the first alternating-current power distribution system in the three alternating-current power distribution systems is connected with the first direct-current circuit breaker in the star-shaped direct-current circuit breaker group through the first direct-current bus-bar; the second alternating-current power distribution system in the three alternating-current power distribution systems is connected with the second direct-current circuit breaker in the star-shaped direct-current circuit breaker group through the second direct-current bus-bar; and the third alternating-current power distribution system in the three alternating-current power distribution systems is connected with the third direct-current circuit breaker in the star-shaped direct-current circuit breaker groupthrough the third direct-current bus-bar. The system of the invention has high reliability. When one direct-current bus-bar breaks down, the remaining distribution network can achieve dual-power-source power supply.