In order to study the effects of bamboo charcoal and carbon-based slow release fertilizer on soil nitrogen loss and bacterial community structure in Moso bamboo forest soil, the concentrations of NH₄⁺—N and NO₃^-—N in leaching water were measured by soil column experiment in laboratory, and the diversity and composition of bacterial community were analyzed. The results showed that compared with the control, the cumulative losses of NH₄⁺—N and NO₃^-—N in the leachate of soil columns with the addition of carbon-based slow-release fertilizer could be reduced by 12.5% and 13.6% (P<0.05), respectively. In addition, the addition of bamboo charcoal could significantly reduce the cumulative losses of NH₄⁺—N, but the effect on NO₃^-—N was not significant. The addition of carbon based slow-release fertilizer could increase the relative abundance of Nitrospira, Nitrospora and Nitrobacter, and increase the relative abundance of Burkholderia, Cupriavidus and Bradyrhizobium which is the dominant denitrification bacteria (abundance > 0.1%) in the lower leaching soil. The leaching effect of carbon-based slow release fertilizer on soil NH₄⁺—N and NO₃^-—N may be closely related to soil nitrogen cycling microorganisms.