Since China officially joined the World Trade Organization (WTO) in 2001, the global economic pattern has gradually changed, from the global value chain to the free trade order, also to the supply and demand of both the international and national financial market. Economic globalization once became a boom in the world economy, but simultaneously, it also brought increasing pressure on the United States as a world-leading economic power. Sino-US power transition gradually has been the main driving factor for the world economic trajectory and the political inclinations of other countries. Different from most previous econometric analysis on certain short time periods or aimed for future event forecasts, this article comprehensively focuses and divides the past 20 years from 2001 to present into four time periods. Selecting four main events, including China’s accession to the WTO in 2001, the 2008 Great Recession, the 2018 Sino-US Trade War, and the ongoing pandemic since 2020 as key nodes, this article first starts from the dyadic level of descriptive analysis to analyze how the Sino-US bilateral competition could manifest their underlying economic power transition. And then, by using the special lens of Free Trade Agreements (FTAs) and the Bilateral Investment Treaties (BITs) signed by the US and China respectively, this study shifts to the network level of analysis to further investigate how two rivals as two poles affected the formation and ensuing intensification of global economic polarization; and how such economic polarization could manifest their power transition over time. Detailed analysis includes the comparison of the change in numbers of agreements, the characteristics of countries involved, and the upgrades of treaties’ contents.