Abstract: With the continuous progress of China’s urbanization, the intensity and negative impact of urban heat island effect are becoming increasingly prominent. So it is of great significance to study the effects of green plant community types on urban cooling. Based on field surveys, multivariate statistical analysis, and the establishment of fitting function model, we have analyzed the cooling effects of four plant community types from plant leaf area index and 3D Green Quantity, to reveal the internal mechanism of the influence of green plant community types on the cooling effect. In summer, plant leaf area index and 3D Green Quantity are adopted in the sequence of four plant community types on cooling effect: arbor-shrub-lawn community > group planting with short tree community > arbor-lawn community > arbor-hardpavement community. The cooling effect of tree-grass and tree with pavement of rigid material have similar function. The community characteristics can be introduced into the mathematical equation model to form a suitable plant community type for landscaping, and the inner mechanism of the influence of vegetation community on cooling effect is illustrated finally, which is one of the innovations of this study.