The typical street canyon- building of the city is the research area. Based on field measurement and numerical simulation CFD(Computational Fluid Dynamics), the airflow pattern and pollutant distribution in street canyon and indoor under the building with windows opening .The result show that the opening of windows on the outer wall of building disturbs

the surrounding air flow, which leads to the enhancement of the vortex flow in the street canyon, local wind direction and wind speed vary in different heights.The turbulence intensity of the buildings facing the street on the leeward side is more obviously affected by the opening of the windows than the buildings on the windward side,1-4 floors were 20.6% higher than

the case of unopened windows.The change of indoor pollutant concentration on each floor is roughly consistent with the outdoor street canyon pollutant distribution, the indoor pollutant concentration of leeward buildings is much higher than that of windward buildings.Concentration of indoor pollutants in leeward buildings decrease with the increase of floors, the pollutants on floors 1-4 account for 43.7% of the total pollution. The indoor pollutant concentration of buildings on the windward side first decreases along the building height, and does not show a monotonous trend of decreasing floor by floor. The concentration value is the smallest near the middle floor of building, then the pollutant concentration increases under the combined action of window disturbance and street canyon circulation vortex. The whole solution of street canyon-window

building overcomes the inconsistency between the inflow level setting of simulated street buildings and the actual working conditions, better solves the problems of complex vortex boundary setting and different from floor to floor in window opening positions.