A new type of suspended filler containing zeolite powder and nitrifying bacteria was proposed in this study. The new filler was used in an enhanced nitrification model experiment of wastewater treatment plant (WWTP), in which three devices were designed with combinations of zeolite powder and nitrifying bacteria. The nitrification performance of the new suspended fillers were evaluated by monitoring changes in NH₄⁺-N, NO₂^--N and NO₃^--N concentration in the three devices. The microbial community structure and diversity in the biofilm of the fillers, furthermore, were analyzed to reveal the nitrification mechanism. The results showed that compared with a single suspension filler containing only zeolite powder or nitrifying bacteria, the composite suspension filler containing zeolite powder and nitrifying bacteria had the highest average removal rate of NH₄⁺-N (68.3%), the lowest average concentration of NO₂^--N (12.62 mg/L), and the highest average concentration of NO₃^--N (7.81 mg/L). Hence, the study demonstrated that the combination of zeolite powder and nitrifying bacteria can significantly improve the nitrification performance of the filler, and zeolite powder may promote the microbial nitrification process. The addition of zeolite powder in the new suspended filler was more conducive to the enrichment and growth of nitrifying bacteria, resulting in the decrease of microbial species diversity. The Nitrosomonas genus in the biofilm of the new suspension filler for enhanced nitrification has an advantage, which provides a strong guarantee for the conversion of NH₄⁺-N in the system. The introduction of zeolite powder in the filler can further promote an increase in the proportion of the Nitrospira genus, thereby reducing the possibility of NO₂^--N accumulation in the system. The purpose of this study was to improve the basis and parameters for the engineering application of new types of suspended fillers.