Purpose <p>Humic acids (HA), a ubiquitous form of natural organic matter in paddy soils, can participate in methane cycling processes. However, systematic studies regarding the effects of HA on anaerobic oxidation of methane (AOM) driven by different electron acceptors are limited.</p> Materials and methods <p>The sampling site was located in Nanjing, Jiangsu Province, China (32.16°N, 118.86°E). This study employed stable isotope probing combined with high-throughput sequencing to systematically investigate the AOM activities driven by various electron acceptors and the effects of HA, and to characterize the associated microbial communities.</p> Results and discussion <p>The results showed that NO₃⁻ served as the dominant electron acceptor for AOM in the 0–10&#xa0;cm soil layer, exhibiting an AOM rate of 6.6 nmol ¹³CO₂ g⁻¹ d⁻¹. In contrast, HA functioned as the primary electron acceptor in the 10–20&#xa0;cm and 20–30&#xa0;cm layers, showing AOM rates of 2.2 and 5.2 nmol ¹³CO₂ g⁻¹ d⁻¹, respectively. The addition of HA enhanced NO₃⁻, NO₂⁻, Fe³⁺, and SO₄²⁻ driven AOM rates by 65%, 152%, 52%, and 120%, respectively. Furthermore, the abundance of ANME-2d archaea was significantly positively correlated with NO₃⁻ content, while NC10 bacteria exhibited the highest abundance in the 20–30&#xa0;cm layer.</p> Conclusion <p>In summary, this study reveals that HA not only serves as a direct electron acceptor for AOM but also promotes AOM processes driven by multiple electron acceptors. These findings provide important insights into the biochemical cycling of methane in paddy soils.</p>