Abstract: In this paper, we introduced the design method for sleeve-type afterbody jet experiment and key aerodynamic characteristics in the design. In order to improve the accuracy of drag measurement for sleeve-type afterbody jet-effect test of a certain aircraft in a high-speed wind tunnel, a seal form and the positions of pressure measurement were elaborately designed at the nozzle annular clearance gap and cross section, respectively. A correction method was applied to the measured drag. The experiment results show that the accuracy of the measured drag is 0.0005. This accuracy is consistent with that in similar jet experiment conducted in abroad tunnel. In addition, the present correction method used is effective for the drag correction in the sleeve-type jet experiment. The measuring accuracy meets the requirement of the GJB (China National Military Standard).