Trump's tax reform, as the largest tax policy adjustment in the United States in nearly thirty years, has sparked widespread controversy since its implementation in 2017. Its core content includes reducing the corporate income tax from 35% to 21%, simplifying personal income tax brackets, and allowing multinational companies to repatriate overseas profits at a preferential tax rate, aiming to stimulate investment, create jobs, and attract capital back to the U.S. In the short term, the tax reform has boosted the rise of the U.S. stock market, reduced the unemployment rate to historical lows, and pushed economic growth rates above 3%, being seen as an important achievement of Trump's early administration. However, its long-term effects are highly questioned: on one hand, the actual effective tax rate reduction for corporations is limited, and a large amount of repatriated funds has not been used for productive investment but instead directed towards stock buybacks and shareholder dividends, exacerbating wealth disparity; on the other hand, the federal budget deficit is expected to increase by more than $1.4 trillion over the next decade, with the national debt-to-GDP ratio approaching historical highs, laying a debt risk for the economy. Furthermore, the global wave of competitive tax cuts triggered by the tax reform has intensified the imbalance in the international tax system, and although the 'territorial tax' system alleviates corporate tax avoidance motives, it has led to a significant shrinkage of foreign capital stock in developing countries, further tearing the global economic structure. Despite Trump’s attempts to continue and strengthen the tax reform during his second term (such as proposing to replace income tax with tariffs), its feasibility is questioned due to inflationary pressures and contradictions in fiscal sustainability. Overall, while the tax reform has temporarily boosted market confidence, it has failed to fundamentally address structural economic problems, instead highlighting the uneven distribution of policy dividends and the deep challenges of globalization governance.