Abstract: This study investigates the grounding of building foundations and external lightning protection systems, using simulation datas to compare test component samples subjected to three fixing methods(welding, appropriate connector technology, and tying). The results of simulated lightning current strike tests on these samples were analyzed to draw relevant conclusions. The aim is to evaluate the lightning protection capability of different connection methods for foundation components in external lightning protection systems. This research provides a theoretical foundation and experimental evidence for the design and optimization of building external lightning protection systems, thereby enhancing the lightning safety of buildings.