Abstract: Investigating the characteristics of the relationship between plant diversity on the floodplain of the Yani Wetland and environmental factors is of great significance for a deeper understanding of the mechanisms by which plants in this wetland adapt to environmental changes. In this study, we employed hierarchical clustering analysis, canonical correspondence analysis (CCA), redundancy analysis (RDA), and Pearson correlation analysis to analyze 22 plant community quadrats in the study area, in order to reveal the relationship between floodplain plant diversity and soil factors. The results show that the plant communities on the floodplain of the Yani Wetland can be divided into two types: the Ass.Myricaria wardii-Orinus thoroldii community and the Ass.Salix cheilophila-Isolepis setacea community. The Simpson's diversity index of the Ass.Salix cheilophila-Isolepis setacea community is significantly higher than that of the Ass.Myricaria wardii-Orinus thoroldii community, while the other diversity indices show no significant differences. Plant diversity in the Yani Wetland is extremely significantly correlated with soil total potassium (TK) and available phosphorus (AP), and significantly correlated with the Shannon-Wiener diversity index, Simpson's diversity index, and Pielou's evenness index. The distribution pattern of plant communities is primarily influenced by soil total potassium, pH, available nitrogen (AN), and available phosphorus. This study aims to reveal the ecological interpretation of the relationship between plant diversity and soil factors in the floodplain of the Yani Wetland, and to provide a theoretical basis for the protection of wetland vegetation and the maintenance of wetland ecosystem stability from the perspective of plant ecology.