Abstract: ABSTRACT：This study addresses the layout and selection of 500kV Hybrid Gas Insulated Switchgear power distribution devices. Taking the Hefei Baogong 500kV Substation as a case, Combined with the actual conditions of Baogong Substation, a comprehensive techno-economic analysis is conducted from multiple perspectives, including footprint, structural design, number of cross-spans, length of branch buses, installation workload, expansion convenience, outage scope, and project cost. The research shows that the linear layout offers advantages such as lower cost, fewer branch buses, and relatively simpler expansion construction, but it involves more complex structures and more cross-spans. The Semi-C-type layout provides clearer wiring, fewer cross-spans, and reduced maintenance workload, but it increases the length of branch buses, leading to higher costs. Under the specific configuration and outgoing line conditions of this project, the land-saving advantage of the semi-C-type layout is not significant, and its investment is approximately nine hundred eighty thousand yuan higher than that of the linear layout. Considering technical feasibility, economic efficiency, and operational maintenance factors, the HGIS linear layout is recommended for the Baogong 500kV Substation. This study provides a systematic comparison method and decision-making reference for the optimal selection of 500kV HGIS power distribution device layouts.