Abstract: Based on the prediction of the influence of aircrafts′ stealth and aerodynamics characteristics by conformal fuel tanks, the method of aerodynamic-stealth design of conformal fuel tanks through a design model was studied, and the effects were compared with the traditional auxiliary tanks. Results show that the conformal fuel tanks bring less bad effects than the traditional auxiliary tanks in the same condition. If well designed, the conformal tanks could improve the performances of the aircraft rather than worsen them. In the designing, the research on the position where conformal tanks placed and the effects was conducted. The experience could be easily extended to other conformal carryings and other type of aircrafts. The rules of aerodynamic-stealth design of conformal fuel tanks were concluded. Based on these results, combined with the characteristics of other carryings, the principles and characteristics of the design of ordinary conformal carryings were also given for consult.