The frequent geopolitical conflicts in recent years and potential value alliance system construction are undermining the efficient functioning and closely dependent global value chain division of labor network. This paper innovatively defines the concept of global value chain vulnerability, constructs the vulnerability index at the economic (sectoral) level and the relative vulnerability indicator at the bilateral level, and explores the amplifying effect of current geopolitical risks on the vulnerability of economies (sectors) in the global value chain. Empirical results have found that the introduction of geopolitical risk with trading partners magnifies an economy"s vulnerability to varying degrees, with a more pronounced "amplification effect" on the United States and some economies that are more dependent on the United States. At the key sector level, for the computer, electronic and optical product manufacturing sector, countries that are important supply hubs along the global value chain, such as the United States, Germany and the United Kingdom, are relatively less vulnerable; for the basic pharmaceutical products and pharmaceutical preparations sector, China shows the lowest vulnerability in the world but is more sensitive to geopolitical risk. The counterfactual simulation analysis of the "US-Japan-India-Australia alliance" shows that the elimination of political uncertainty among member states has a very limited role in improving the security of member states" participation in global value chain; if the four-nation alliance escalates to a consistent relationship with China, it will increase the vulnerability of the United States, Japan and Australia.