Abstract: Taking the herbaceous plants in the ecological conservation area and rational utilization area of Nanmenxia Wetland Park as the research object, 20 quadrats in 5 plots of Nanmenxia Wetland Park are surveyed by using typical sampling method and random sampling method, and their species composition and diversity are analyzed. The results show that there are 24 families, 64 genera and 90 species of herbaceous plants in the plot. The number of single-species families and genera is the highest. The Margalef index of Chaba Gorge is the highest in each region, the Margalef index of Juancao is the lowest. The Pielou index is relatively low, and the Pielou index of Juancao sample is the lowest. The sample point of the wetland experience area is the lowest in the coiled trough sample. The Shannon-Wiener index is the lowest in the Juabcao sample and the highest in Chaba Gorge. Biomass in the park shows a trend of first increasing and then decreasing over time. Among the points, the biomass of Chaba Gorge is the highest and the reservoir is the lowest.The Shannon-Wiener index, Margalef index, and Pielou index have a significant positive correlation, and the Shannon-Wiener index has a positive correlation with biomass and altitude. The main reason affecting herb diversity in Nanmenxia wetland parks is the difference of regional habitats.