Abstract: There exists some operational problems of the πT hybrid structure, such as large workload of operation and maintenance, flexibility and poor scalability, which can not meet the increasing demand for power supply reliability. In this paper, the problems existing in the actual operation of the πT hybrid structure are analyzed in detail, and the optimization scheme of the chain type π connection structure is put forward, and the technical and economic demonstration of the optimization scheme is carried out. This paper also studies the concrete alteration scheme of πT mode to chain π connection mode, realizes the smooth transition of networking mode, and establishes the networking principle of 110 kV power grid, directs the implementation and landing of the optimization of the 110kV power grid with πT hybrid structure.