Despite the rise of trade protectionism from time to time in the process of economic integration, G20 member countries have formed a unique trade network structure as cooperation strengthens. Based on the import and export trade data of G20 countries between 2000 and 2016, this paper analyzes the spatial relationship among G20 countries’ export trade and its network effect, and then the contribution of G20 countries’ trade to national economic growth. The research shows that the spatial correlations of G20 countries exhibit a multithreaded network structure, and the network efficiency and network level are overall stable. The centrality of China, India, Brazil, Russia and the United States are relatively higher. Such network structure characteristics are reflections of free trade. G20 countries can be grouped into four categories in terms of “twoway spillovers”. An indepth quantitative analysis also finds that closeness centrality has a positive facilitating effect both on trade and economy, which is different from the effects of degree centrality and betweenness centrality. 