To explore leaf functional traits, species diversity, and functional diversity characteristics and correlation of plant community in Tiankeng forests will help to build the context of leaf traits, species diversity, and functional diversity research context, and further understand the process and functions of the ecological system in the negative terrain forest, and provide a scientific basis for restoration and reconstruction of the vegetation in degraded karst areas. This paper takes the woody plant community in three habitats (the inside of Tiankeng, the fringe of Tiankeng, and the outside of Tiankeng) of Dashiwei Tiankeng Group as the object, to study the leaf functional traits, species diversity, functional diversity characteristics and their interactions, through community investigation and leaf functional traits measurement. The results are as follows:(1) woody plant grown in the inside of Tiankeng shows the highest specific leaf area (SLA:198.75 cm²/g), leaf area (LA:42.70 cm²), leaf phosphorus content (LPC:1.70 g/kg) and leaf potassium content (LKC:10.27 g/kg), in the outer of Tiankeng presents the highest leaf tissue density (LTD:0.32 g/cm³) and leaf dry matter content (LDMC:0.41 g/g), and the growth of woody plant is limited by P in Tiankeng forests and nearby karst forests. With the variation of habitats from the inner to the outer of Tiankeng, partial adjustments are made in the adaption mechanism and survival strategy of the woody plant. A quick defense strategy on investment for the species increases, while a slow growth strategy on investment of species is weak. (2) Shannon-Wiener index (2.82), Simpson index (0.92) and Pielou's evenness index (0.87) in the outside of Tiankeng are the highest, and the functional richness index (1.05), function dispersion index (1.88) and Rao's quadratic entropy index (4.52) in the inside of Tiankeng are the highest. With the variation in the inner-edge-outer habitats of Tiankeng community, the differences in plant functional traits reduce, the range of species distribution and functional traits are steady, and the individual of species increases. (3) There is significantly correlated to each species diversity and functional diversity, indicating that there are different restrictive relationships between species diversity and functional diversity. (4) The leaf functional traits are significantly correlated with species diversity and functional diversity, and the correlation between species diversity and functional diversity is weak, indicating that leaf traits are more sensitive to variation of ecological processes and there is a strong coupling relationship between leaf functional traits and species diversity.