Abstract: An injection flow method for drag reduction is presented. The injection channel from the leading to the training of the Airship is made. Part of outer flow is conducted to flow out through the injection channel. Based on the Reynolds-Averaged Navier-Stokes equations with SST turbulent models, the flow field around airship with the injection flow through the station points is computed. The flow field with different injection radius and different entrance mouth shape is simulated. The results show the injection channel can improve the flow effectively and reduce the flow separation around the airship. The drag coefficient of the airship is reduced sharply. The radius of the injection channel is between one fifteenth and one thirtieth of the maximum thickness of the airship, whose change has small influence on the out flow around the airship. Moreover, the small change of mouth shape does not affect the outflow either.