Abstract: Traditional breaker-and-half（3/2） connection scheme is a high-reliability scheme which is widely used in power system, while when "N-2" situation happens（such as "Double Fault-trip" or "Maintenance Outage + Fault-trip"）, the connectivity of other operation circuits might be destroyed, this will affect power delivery of key power channels and might cause cascading trips. This paper proposed schematic and layout drawing of novel decentralized bus-free breaker-and-half connection scheme which is based on 3-regular graph, and the investment of the novel scheme is less than traditional breaker-and-half scheme while the above connectivity problem will not be exist. For the novel scheme, the ratio "Number of CBs/Number of External Circuits" is 1.5/1 which is the same as traditional breaker-and-half scheme, while the bus-bar（i.e. key convergence point） will not be existing, this will avoid the influence of bus-bar outage and related investment in primary system and secondary system. In the novel scheme, each external circuit was connected with the main connection via 3 CBs, thus when 2 external circuits outage, other operation circuits will still be connected, this implies that the novel scheme will enhance the reliability of power system when "Multiple Fault-trip" or "Maintenance Outage + Fault-trip" happens, and further eliminates or reduces the possibility of adverse chain reaction happens. At last, this paper implemented a comparative analysis of two traditional representative high-reliability connection schemes（double-bus double-section connection, traditional breaker-and-half connection） with novel connection scheme on several aspects such as cost and reliability, which shows that the novel scheme has significant advantage in terms of technology performance and cost-effective.