Wind environment and pollutant dispersion mechanisms in Central Business Districts (CBDs) play a crucial role in urban sustainable development. This study, based on ENVI-met numerical simulation technology, systematically analyzes the regulatory mechanisms of building density, green space ratio, wind incidence angle, floor area ratio (FAR), and street aspect ratio on PM2.5 concentration distribution, using typical CBDs in China's major economic regions as the research subjects. The results indicate that: a. The optimal operational conditions for building density and green space ratio are 30%, with increased building density significantly exacerbating pollutant accumulation; b. A wind incidence angle of 45°–75° can enhance ventilation efficiency (average wind speed increase of 17%), and increasing the street aspect ratio from 1 to 2 can expand the area of excellent air quality by 5%; c. The floor area ratio exhibits a nonlinear response to pollutant dispersion (fluctuation amplitude of 23%), necessitating differentiated design based on site-specific wind conditions. The ranking of factor correlations is: building density > green space ratio > wind incidence angle > floor area ratio > street aspect ratio. The research findings provide a scientific basis for optimizing planning parameters and improving microclimate environments in CBDs, offering practical guidance for enhancing urban living environment quality.