The skeleton layout design of assembly jig needs to consider the constraint relationship with assembly products and locators or clamps. Therefore

the design process is complicated and difficult to achieve optimal design. In order to improve the design efficiency and design quality of the skeleton

an optimal layout design method for aircraft assembly jig skeleton based on least square is proposed in this paper. Firstly

the optimal mathematical model of skeleton optimization layout is established based on least square method; then the optimal solution algorithm of the model is established under the different positioning feature distribution situation of assembly products; finally

the optimal layout algorithm of the skeleton is realized based on CATIA system and CAA technology

the effectiveness of this algorithm is verified by the aircraft wing and front fuselage products. The algorithm makes the skeleton layout design simpler and faster

and also be the optimal design result

which can effectively shorten the design cycle and greatly improve the design quality.