The construction industry faces significant challenges due to changes in the economic environment, making high-quality development a crucial area of research. This study examines the impact of economic policy uncertainty on corporate performance using financial data from the construction industry collected between 2000 and 2020. By constructing a multiple linear regression model, it explores the moderating and mediating effects of financial slack on this relationship. The results show a significant negative correlation between economic policy uncertainty and corporate performance. However, financial slack can reduce the negative impact of this uncertainty on corporate performance. By effectively managing financial slack, companies can mitigate the adverse effects of economic policy uncertainty. These findings provide a theoretical basis for businesses to optimize management decisions, improve resource allocation efficiency, and enhance corporate performance.