<p>Bilateral tax treaties (BTTs) are the basis of the current international tax coordination model and the most important governance vehicle of the global tax governance (GTG) system. This study constructs a comprehensive database of BTTs encompassing 205 countries/regions from 1950 to 2020 and employs complex network analysis to examine the spatio-temporal evolution of the GTG patterns. We focus on governance models, regional organizational structures, and national roles. Research has found that the GTG system is evolving from centralization to polycentricity, with a trend toward defragmented, polycentric, and complicated. In the GTG landscape, there has been no significant change in the dominance of developed countries in formulating international tax rules. However, there is a tendency for the center of governance to shift from the Group of Seven (G7), representing the traditional powers, to the Emerging Seven (E7). The GTG pattern has undergone scale rescaling, with a significant trend of regional integration. The geographical diffusion of the structural power of GTG presents the Matthew effect. The advantages of Western European countries are strengthened, the disadvantages of South American and African countries continue, and the structural power of BRICS countries is catching up. Based on these findings, this paper develops a multi-dimensional analytical framework of driving factors, identifying four core mechanisms—regional and historical ties, institutional diffusion, investment-driven effects, and network structure—and reveals the multi-scale interactions within the global tax governance network.</p>