Abstract: The nuclear power plant is connected to the 500kV main switch station through the connection of the generator-transformer unit, and then connected to the local power grid through the 500kV main switch station. There are multiple ways to connect the main transformer to the 500kV main switch station. With the increasing maturity and widespread application of 500kV high-voltage cable technology, this article provides a detailed comparison and explanation of two connection methods for nuclear power plants: 500kV Gas Insulated Line (GIL) and 500kV high-voltage cable, based on collected experience feedback and equipment data. Technical and economic recommendations are given.