The effect of blade mistuning is inevitable in the realistic bladed disks of aero-engine system. It has a bad influence on the characteristics of vibration, also on the working performance and the lifetime of whole aero-engine. By analyzing the blades arrangement, it is observed that the different blades ordering for a group of given mistuning blades can make an obvious impact on the vibration of bladed-disk system. Based on what mentioned above, a new localization parameter method is proposed to manifest the localization level of mistuned bladed-disk. Meanwhile, by applying artificial ant colony algorithm, the ordering of blades is optimized when assembled. The research shows that an appropriate choice of the arrangement order can reduce the amplitude and localization level of the forced vibration effectively,and that the analysis method used in this paper is feasible and effective.