In order to explore the mechanism and effect of urban greenbelts on reducing air particulate matter, the green space of Luojiagang Greenbelt Park in Wuhan and its surrounding built environment were selected as the research object. Three days with clear and windless weather and similar meteorological conditions in winter were selected for repeated observation. The method of combining LUR model and principal component analysis was used to analyze the mitigation effect of urban greenbelt on air PM10 and PM2.5 concentrations in winter, and to identify the key influencing factors, aiming to provide scientific basis for the planning and construction of urban greenbelt built environment. The results show that based on the LUR model, the mitigation effect of urban greenbelt on air PM10 and PM2.5 will be disturbed by the surrounding traffic pollution emissions, and the microclimate conditions created by urban greenbelt with different widths will also have a certain impact on the concentration of air PM10 and PM2.5. The research shows that the greenbelt has a width effect on the mitigation of air PM10 and PM2.5, and the green space with a width of 30?40m has the most significant reduction efficiency of air PM10 in winter. At the same time, the study found that the concentration of air PM10 and PM2.5 in the urban green belt in winter will be higher than that of the adjacent road position, and there is a significant accumulation effect of air PM10 and PM2.5 in the urban greenbelt. It will provide important scientific guidance for the high-quality development of the PM retention effect of the urban greenbelt along the road.