This analysis assesses the relationship between anti-corruption efforts and China’s economic growth, employing Fixed Asset Investment by the Whole Society (FAI) as a key explanatory variable. Using panel data from 32 provinces (2000–2020), the study employs fixed-effects regression, moderation effect models, and threshold regression to analyze the interplay between corruption, investment, and growth. The study identifies a mutually reinforcing dynamic where anti-corruption initiatives and FAI jointly enhance their respective growth-promoting effects. Empirical evidence suggests that achieving specific threshold values in FAI significantly magnifies the economic benefits derived from anti-corruption policies. These findings provide actionable guidance for economic governance strategies in developing economies.