Aiming at the operation mode of 110 kV ring network, this paper analyzes the problems existing in the traditional protection configuration scheme, and advances a comprehensive backup protection device for busbar. The comprehensive backup protection of 110 kV line is proposed by using the bus connection breaker′s trip signal of the transformer′s far backup protection, and integrated with the failure protection of the circuit breaker to form a complete solution. When 110 kV line occurs faults, the device can effectively prevent the transformer backup protection′s no selective overstep tripping by current breaker because of the rejection of the single line protection device or the failure of the circuit breaker, reducing the power outage range and improving the reliability of the power supply. Results of simulation and prototype experiment verify the effectiveness of the proposed theory and control strategy.