Abstract: Freshwater ecosystems are facing severe biodiversity loss, which is being further intensified by climate warming and anthropogenic environmental disturbances. To explore the effects of multiple environmental stressors on macrozoobenthos community structure and biodiversity, a three-factor mesocosm experiment was conducted, including warming (ambient temperature vs. +2℃), food web simplification (complex vs. simplified food webs), and surface runoff pulse disturbance (with vs. without). The results showed that surface runoff pulses significantly increased the total abundance of macrozoobenthos, whereas no significant effects were detected on total biomass. At the taxonomic level, surface runoff pulses significantly increased the abundance and biomass of Chironomus sp., while the interaction between warming and food web simplification significantly enhanced the abundance and biomass of Helobdella nuda. Regarding biodiversity, surface runoff pulses significantly decreased functional richness, and average taxonomic distinctness, whereas food web simplification also negatively affected functional richness. Correlation analysis revealed that species diversity, functional diversity and taxonomic distinctness diversities were generally positively correlated, indicating broadly consistent response among different dimensions of biodiversity. Overall, under the experimental conditions applied in this study, surface runoff pulses played a dominant role among the multiple stressors, simultaneously increasing community abundance while reducing multidimensional biodiversity. This study elucidates the response mechanisms of macrozoobenthos community structure and multidimensional diversity under multiple environmental stressors, providing a theoretical basis for biodiversity conservation and management in freshwater ecosystems.