Abstract: Urban green infrastructure (UGI) plays an important role in mitigating PM2.5 particulate pollution and providing other ecosystem services. In the light of the research findings of the research group on the relevance of UGI and PM2.5, this paper takes Jianghan District of Wuhan City as the object to put forward a spatial recognition idea of UGI network planning practice based on the GIS platform. It proposes UGI optimization measures for high-density blocks based on PM2.5 reduction from two perspectives: increasing the number of green spaces in the block and optimizing the form of green space. The results show that the green coverage rate increased from 23.35% to 29.96%, and the 3D green amount reached approximately 1.15 km2; the core and bridge connections increased by 5.84% and 1.15%, and the islets decreased by 4.32%. The deceleration rate of PM2.5 and excellent days in 2018 in Jianghan District were markedly improved. It is the first attempt to apply the theoretical research results related to PM2.5 and green space in block UGI planning, proposing a new idea of urban block-scale UGI network optimization oriented by PM2.5 reduction.