The effect on the air film drag reduction effect of van body by jet velocity of seeping air flow on van body surface was studied.Film air jet velocity of van experimental model with air film was controlled by air film generation system to carry out resistance measurement contrast experiments of models with and without air film in variablespeed laminar flow wind generator with an air flowing speed of 30 m/s.The resistances of experimental models in the different ejection velocity were compared.Experimental result shows that in a condition of constant speed of laminar flow wind,seeping air flow on van body surface can effectively reduce wind resistance on van body.In a certain range,the drag reduction rate is increased with increasing of jet velocity as approximately linear growth.