Abstract: Understanding the response of wetland plant community structure and diversity to environmental factors is crucial for the conservation and restoration of floodplain wetland ecosystems in the Yellow River. This study examined the natural plant community structure in typical floodplain wetlands along the Ningxia section of the Yellow River, emphasizing plant community composition, diversity distribution across different microtopography levels (high, medium, and low), and their responses to environmental factors, including soil physicochemical properties, micro-elevation, and groundwater level. The study identified 25 plant species from 24 genera and 14 families, indicating relatively low species richness. From June to September, the Margalef richness index, Shannon-Wiener diversity index, Simpson dominance index, and Pielou evenness index showed similar trends, increasing with microtopography. The plant community structure exhibited a clear correlation with Digital Elevation Model (DEM) elevation data, with vegetation transitioning from Phragmites australis + Acorus calamus communities to Phragmites australis, Phragmites australis + Typha minima, Salix matsudana + Phragmites australis, and Phragmites australis + Tripidium arundinaceum communities as surface elevation increased. Correlation and principal component analyses indicated that plant diversity was strongly positively correlated with micro-elevation and groundwater level (p<0.01), highlighting them as key factors shaping plant community distribution in floodplain wetlands. Additionally, soil moisture content and salinity significantly influenced plant diversity distribution patterns. The findings of this study contribute to a deeper understanding of the intrinsic mechanisms underlying wetland plant community formation, filling critical research gaps regarding the impacts of microtopography and environmental factors on plant community diversity in floodplain wetlands. And the study further enriches the theoretical framework of plant community ecology. The study demonstrates dual practical significance: Firstly, it provides scientific justification for employing microtopography modification in floodplain wetland restoration projects, thereby facilitating rapid reestablishment of plant communities and enhancing the wetland rehabilitation. Secondly, it establishes theoretical foundations and technical references for ecological restoration and biodiversity conservation of the Yellow River floodplain wetland systems in inland arid regions. These findings enable regulatory authorities to formulate scientific wetland conservation and management strategies, effectively mitigating anthropogenic-induced challenges, including wetland area reduction and degradation of ecological functions. Moreover, the study propels the development of sustainable regional ecological environments through optimized ecosystem management approaches.