Multi-zone airflow modeling uses some simplifying assumption which ignores the influence of airflow rate by different door position. And it would lead to large error in airflow rate calculation. This paper compares airflow rate through the models with door position in the middle and at the sides in different window opening ratio conditions by wind tunnel experiment. After comparing simulation model result with experimental model result, the numerical simulation is researched in different conditions:no door、front door、back door、front and back doors. The airflow rate through the models with different doors position is compared. Experimental results show that the effects of airflow momentum can't be ignored but only the window opening ratio small enough, or the free space jet or confined space jet models need to be compared, and the largest jet length is used to optimize multi-zone airflow model's results.