To discuss species diversity, functional traits, stoichiometric characteristics and correlation of plant community in the forest will help construct the structure-trait-function research context, further understand the process and functions of the ecological system, and provide a scientific basis for the optimal allocation and regulation of the community structure. This paper takes the plant community in four stages (herbage-shrub, shrub, tree-shrub, tree) of succession of karst plateau canyon as the object, to study the species diversity, functional traits, stoichiometric characteristics and their interactions, through community survey, functional traits and ecological stoichiometric measurement. The results show that: (1) Shannon-Wiener index and Pielou evenness index in the tree stage are the highest, reaching 8.62 and 2.41, respectively, suggesting that with the succession of community, the uniformity of species distribution increases. (2) Among the species diversity indexes of plant community, Margalef richness index and Simpson dominance index are not significantly correlated (-0.644), and the rest are in a significant or highly significant correlation, suggesting that there is a strong promoting or inhibitory effect among indexes of species diversity. (3) Leaf thickness and rest indexes, as well as species diversity index, functional traits and ecological stoichiometry are not significantly correlated, while specific leaf area (SLA) is only in a significant correlation with soil N ∶ P (0.742), indicating that there is a weak correlation among species diversity, functional traits and ecological stoichiometry of community. (4) The SLA in shrub stage is the highest (272.13 cm²/g), δ¹³C is a little higher in later stage of succession, and it is co-limited by N and P in herbage-shrub and shrub stage, suggesting that with the progress of succession, certain adjustments are made in the adaptation and resource utilization strategy of plants, meaning that there is a strong covariant relationship between plants and environment. (5) During the forest cultivation, tree, shrub and herb layer shall be constructed to improve the self-regulation ability of the ecological system, covering the mineralization, transformation and circulation of nutrients.