[Objective] The intrinsic mechanisms underlying the spatiotemporal heterogeneity of nutrient removal efficiency and the regulatory role of aquatic plant rhizosphere effects in micro-scale surface flow constructed wetlands （SFCWs） remain unclear. This study aims to address the following issues： （1） Elucidate the spatiotemporal distribution patterns of nitrogen （N） and phosphorus （P） removal efficiency； （2） Reveal the correlation mechanisms among microbial community structure， metabolic potential， and N/P removal； and （3） Evaluate the effects of the plant rhizosphere and three typical plant species on microbial community structure and N/P metabolic potential， providing a basis for the design and maintenance of micro-scale SFCWs. [Method] Using a specific wetland as a case study， water quality monitoring and high-throughput microbial sequencing were employed to systematically analyze the spatiotemporal characteristics of N/P removal and their microbial driving mechanisms. The regulatory mechanisms of substrate types and plant rhizospheres on microbial community composition and metabolic potential were also clarified. [Results] （1） The ammonia nitrogen removal rate remained stable （89.3%-95.8%）， while the total nitrogen removal rate exhibited seasonal variation： summer （75.6%） > autumn （64.9%） > spring （54.3%） > winter （21.9%）. This process was closely related to the succession of functional bacterial communities and changes in metabolic potential. N-cycling functional bacteria， including Kosakonia， Bacillus， Noviherbaspirillum， Ellin6067， and Anaeromyxobacter， were significantly enriched in spring and summer， resulting in significantly higher N metabolic potential compared to autumn and winter. （2） The total phosphorus removal rate， co-regulated by microbial action and adsorption/sedimentation， showed seasonal variation （summer 74.9% > spring 65.6% > autumn 59.8% > winter 46.7%）. Microbial influence on seasonal fluctuations was evidenced by the significant enrichment of P-cycling functional bacteria， such as Massilia， Bacillus， Saccharimonadales， and Gemmatimonas， in spring and summer， with P metabolic potential significantly higher than in autumn and winter. （3） Spatially， N/P metabolic potential demonstrated stability. Although substrate types （gravel， non-rhizosphere soil， and rhizosphere soil） significantly altered bacterial community composition， no significant differences in N/P metabolic potential were observed among substrates. This provides empirical evidence for the weakened rhizosphere boundary effect and the maintenance of metabolic homeostasis via functional redundancy at specific scales in micro-scale wetlands. [Conclusion] In space-constrained SFCWs with low pollution loads， water temperature dominates the biochemical reaction rates of N/P transformation. Alkaline pH and an appropriate increase in total nitrogen concentration synergistically promote P removal. Microbial community distribution is influenced by nutrient substrates and environmental factors. Based on these findings， the following optimization strategies are proposed： （1） Install a pre-treatment unit for total phosphorus at the inlet to mitigate the risk of endogenous release caused by substrate saturation； （2） Utilize aquatic plant root systems to promote the enrichment and spread of denitrifying bacteria， while reducing the reliance on precise plant species configuration； （3） Based on the succession characteristics of functional bacteria， apply targeted inoculation of highly efficient microbial agents for N/P removal； and （4） Maintain stable system operation through water temperature regulation， pH optimization， and nutrient load management.