In order to study the influence of hole spacing layout on the air film drag reduction effect of van body surface,a passive air film generator was designed by optimizing van model.Under the condition that the diameter of seepage hole is 1 mm and the inclination between hole and chamber surface is 90°,the total resistance of the chamber model with longitudinal spaces of the small holes from 11 to 3 mm and transverse distance of the small holes from 11 to 5 mm was tested by simulated wind tunnel test with or without the seepage of the van surface.The results show that the longitudinal spaces of the small holes have little influence on the drag reduction effect.The drag reduction effect of the van body surface is increased first and then decreased with the increasing of the lateral spaces of the small holes,and the best drag reduction effect is obtained when the hole lateral space is from 11 to 3 mm.The drag reduction effect is decreased with the increasing of mainstream speed and seepage speed when the ratio of mainstream speed and seepage speed is equal.