Based on institutional theory, this study empirically examines the impact of social trust on corporate ESG rating divergence and its underlying mechanisms using a sample of A-share listed companies in China from 2018 to 2022. The findings reveal that social trust can significantly reduce corporate ESG rating divergence. Mechanism tests indicate that social trust helps improve both the internal and external information environment of enterprises, thereby mitigating ESG rating divergence. Further analysis demonstrates that the inhibitory effect of social trust on ESG rating divergence is more pronounced when companies exhibit stronger internal controls, operate in regions with weaker marketization, have executives with higher environmental awareness, and face greater public environmental concerns. Additionally, social trust shows more significant alleviating effects on rating divergence in the social and governance dimensions of ESG. Economic consequence tests suggest that by mitigating ESG rating divergence, social trust ultimately enhances corporate performance and capital market performance.