In the process of designing and manufacturing of aircraft

a reasonable assembly tolerance allocation is an effective way to improve the assembly accuracy

decrease the manufacturing cost and increase the success ratio of assembly at one time. So

fi rstly the multi-objective optimization model of assembly tolerance oriented on the assembly performance

the manufacturing cost and the assembly complexity is presented here. Secondly

a new method combined Analytic Hierarchy Process (AHP) with Particle Swarm Optimization (PSO) algorithm is employed to solve the multi-objective optimization model by using AHP to determine the weight factors and get the optimization model as a fi tness function. Finally

the method is applied in a fl ap component assembly tolerance for a certain type of aircraft

which proves the optimization results can meet the design requirements and improve assembly tolerance effi ciency.