Although the influence of tree canopy usually can not be ignored in the research on the wind environment around buildings,the numerical simulation of the turbulence flow over a vegetated surface is rather complicated.The method of adding additional source/sink terms in the turbulence and momentum transport equations combining with the roughness modification of wall boundary was applied to appropriately model the effect of the tree canopy.Firstly,the new additional source term model for the turbulence frequency ω equation in the ShearStress Transport (SST) k-ω model was proposed theoretically.Secondly,the new model was numerically verified by comparing with the experimental results of the windbreak flow.At last,the proposed source term model was employed in the optimization design of the wind environment around highrise buildings.It is concluded that the new source term model is accurate and applicable for modeling the canopy flow,which provides a reference for the similar numerical researches on wind environment.