Reasonable greenbelt setting can change the air flow field, effectivelyoptimizing air quality. In this study, the effects of crown profiles and location of green belts in street canyon were explored by using wind tunnel and numerical model. In numerical part, an innovative method, assigning different leaf area density (LAD) values to different heights of plant models, was used to simulate the crown profiles in the numerical model, and then the pollution source data was input into the simulation system to calculate the wind field data and pollutant concentration data. After simulate calculation, the numerical model was verified by comparing data from simulation results with the the data obtained from wind tunnel experiment. At last, pollutant exposure characteristics of pedestrians in street canyons under different green belts settings were analyzed using the numerical model. The results show that the differences between green belts lacation and crown profile will affect the vortex structure in the street canyon, resulting in complex turbulence, which affects the wind environment and the pollutant distribution in the street canyon. The deciduous profile and the one central green belt are effective in reducing the pedestrians pollutant exposure. In future study, more monitoring points should be set in the wind tunnel and the influence of thermal and meteorological factors should also be embededinto simulation and wind tunnel experiment, so as to provide a more detailed configuration of the green belt in street planning to alleviate the pollution inthe microenvironment in street canyons, and provide better scientific basis for local atmospheric environment management and the design of urban green space.