Air distribution in passages between residential buildings have important influence to people's comfortable, but it is difficult to study because of the variety and the complexity of the outdoor environment. Generally, people use CFD numerical simulation to study air distribution in passages, the key is how to ensure the accuracy of the CFD numerical simulation. The paper considered the effect of computational domain area, roughness, surrounding buildings and high mesh resolution to CFD calculation results, and analyzed the Influence degree of these factors. In addition, the article selected two test points in Xi’an Vanke residence community, and proceed the continuous measurement of wind speed and direction about two months. Through the comparison of CFD numerical simulation and experimental data, the paper validated the accuracy of CFD numerical simulation. It is found that roughness has the most important influence on the result, but we can't ignore the influence of surrounding buildings, computational domain area.