Rubber tree powdery mildew, a major fungal leaf disease of Heveae brasiliensis trees caused by obligate parasitic fungi (Erysiphe quercicola), is among the most important diseases affecting rubber planting areas worldwide. Phyllosphere microbiomes are currently a new research hotspot in molecular ecology, and their biological community is extremely rich. This study used high-throughput sequencing and other molecular techniques to analyze the structure and diversity of dominant fungi and bacteria in the communities of rubber tree leaves (N=16) in four representative rubber-producing regions in Hainan Province, China, after the occurrence of white powder disease. The sampled area had high species richness and stable biodiversity. This study mainly focused on (i) the dominant bacterial and fungal phyla and genera of the sampled regions; (ii) differences in the phyllosphere microbial community structure and relative abundance between healthy leaves and powdery mildew Level 3-diseased leaves within the same region; and (iii) differences in the phyllosphere microbial community structure and relative abundance between healthy leaves and diseased leaves, as well as their correlations with environmental factors, in different regions. This work is innovative in three respects: (i) distinguishing the dominant populations of phyllosphere microbes for rubber trees with powdery mildew via high-throughput detection technology to determine the impact of powdery mildew on these microbes; (ii) exploring the effects of pathogenic bacteria on phyllosphere microbes and hosts from a relatively macro perspective; and (iii) investigating the effects on phyllosphere microbial communities before and after the infection of obligatory parasite leaf pathogenic bacteria. This project is among the first conducted in China’s representative rubber-producing areas to study Erysiphe’s influence on rubber tree leaf microorganisms. These findings provide data support to better understand the biological evolution of powdery mildew diseases and establish new strategies for their ecological control in rubber tree plantations.