Transmission line configurated with line disconnector in 3/2 connection mode usually may be independently equipped both line protection and stub protection. The line protection and stub protection should be enable/disable manually while the line disconnector is operated for different system operating modes. The disadvantages such as high complexity and low reliability of traditional configuration for 3/2 connection are analyzed， and a new design of line protection is presented. Line protection and stub protection are integrated in the new design and the strategy and zone of protection can be adjusted automatically through acquiring the position of line disconnector. The primary circuit and second circuit are simplified for this design with higher economy and reliability.