The rationality of a tolerance allocation plan ensures the efficiency and quality of aircraft products. A typical aircraft wing box is selected as the study object

and its assembly processing technique is analyzed. Based on the three dimensional tolerance analyzing software 3DCS

the 3D tolerance analyzing model is built and the assembling process is simulated. Then

the tolerance allocation plan is designed and optimized. Besides

the structuring display of the 3D tolerance model is implemented and the mechanism of interactive rapid adjustment for the model is established based on the development tool CATIA CAA.