Unevenness between margin of strength and stability of cylindrical shell is a common problem in design. To study this issue, the multi-objective optimization model based on the weighted-sum margin of ring stiffened cylindrical shell is constructed. The margins of attributes are constrained to make the margins among the attributes more even. The modified lexicographic method is used to gain the optimum solution. The results show that the allowable stress of ring influences the feasible solution space, the constrain of stress of ring is the main constrain. The effects of the allowable stress of ring on optimum results are studied. The numerical results suggest that the unevenness between margin of strength and stability can be solved by loosening allowable value of stress of ring properly.