<p>As an important indicator affecting the formation of soil organic carbon (SOC), microbial carbon use efficiency (CUE) characterizes the potential of soil carbon storage. Clarifying the effects of different cropland management on microbial CUE helps us to more accurately estimate the carbon dynamics in cropland soil. By conducting a meta-analysis of 218 pairs of measurements from cropland, we found that conventional management (sole chemical fertilization) and optimized management (straw incorporation, combined application of chemical fertilizers and organic amendments, no-tillage or reduced tillage, etc.) significantly increased microbial CUE by 16.6% and 9.9%, respectively. Changes in soil carbon-to-nitrogen ratio (C/N ratio) and SOC contents were important factors influencing microbial CUE responses to conventional management. Specifically, the response of microbial CUE increased with the elevated response of soil C/N ratio but decreased with soil total nitrogen contents, suggesting that the continuous increase in soil total nitrogen contents due to nitrogen fertilization would lead to a decline in microbial CUE under conventional management. The change in soil C/N ratio was the best predictor of microbial CUE responses to optimized management. The impact of mean annual temperature on the response of microbial CUE depended on cropland management. Specifically, mean annual temperature exerted a negative influence on the response of microbial CUE under conventional management but a positive effect under optimized management. Overall, our findings highlight the differences in the regulation of environmental factors on microbial CUE responses to different cropland management, which can improve our understanding of the effect of different cropland management on soil microbial CUE.</p>