Abstract: The shape, the height and the installation location of the wake rake have some influence on the airfoil drag when the airfoil drag is measured by the wake integral method in the wind tunnel experiment. The airfoil experiments have been carried out in NF-6 transonic wind tunnel for two wake rakes with different heights respectively at two installation locations in the experimental section with the OA309 airfoil. By comparing and analyzing the experimental data of different installation locations with the same height of the wake rake and the experimental data of wake rakes with different heights at the same installation location, the suitable combination of the wake rake height and the installation location needed for different experimental conditions has been obtained, which provides references for drag measurement in the transonic airfoil wind tunnel.