This study investigates whether and how corporate social responsibility (CSR) affects stock liquidity. Utilizing panel data from 3,366 Chinese enterprises spanning 2010 to 2021, empirical findings suggest that CSR endeavors facilitate an uplift in stock liquidity. Specifically, a 1% increase in CSR score will improve stock liquidity by 0.128%. The research further reveals that media coverage and corporate operations are crucial channels for CSR to affect stock liquidity, with the former playing a more dominant role. Notably, the bolstering effect of CSR on stock liquidity is amplified during periods of increasing economic policy uncertainty. Heterogeneity analysis reveals that the influence of CSR on stock liquidity is particularly salient in state-owned enterprises. Additionally, different CSR subcategories (shareholder responsibility, employee responsibility, and social responsibility) vary in their effect on stock liquidity. Shareholder and employee responsibilities both enhance stock liquidity, with the impact of shareholder liability being particularly pronounced.