Abstract: Q/GDW 175-2008 standardization design specification for power transformer, high voltage shunt reactor, busbar protection and auxiliary equipments published by State Grid is analyzed in this paper, and the new standardization of busbar protection is also explained. The standardizations analyzed in detail are the judgment criteria of current and protection region for failure protection, the specification of busbar protection when breaker works incorrectly and the combined action of main transformer protection, the reason for the protection design of charging to dead zone protection, the cooperation between charging protection and busbar protection, the action locking criteria of tie switches in busbar protection, and the anti\|misoperation criteria of direct action breakers in busbar protection. The analysis is helpful for understanding the standardization design specification for busbar protection and auxiliary devices.