For the problems such as high uncertainty in assembly accuracy transmission and post-assembly forced alignment by the current assembly coordination methods that are mainly based on geometric quantity control

this study investigates the cumulative transmission mechanism and quantitative evaluation methods of assembly coordination errors that incorporate the practical error state. Firstly

the deformation during the assembly process of aeronautical thinwalled parts was analyzed

and an error transmission path model for flexible assemblies was constructed based on the symbolic matrix of flexible mating surfaces. Secondly

based on the small displacement torsor theory and homogeneous transformation theory

an initial deviation transmission calculation matrix was constructed. By obtaining the multi-physical field coupling deviation in real-time

the deviation transmission factors were dynamically updated during the assembly process and the transmission calculation matrix w as corrected to accurately calculate the assembly error. Furthermore

with the help of the stability entropy function

a comprehensive evaluation system was established with the assembly error value as the leading indicator

and the local entropy value as the additional indicator

and the accurate evaluation of the cumulative error state on the thin-wall surface could be achieved. Finally

a wing-box structure was taken as an example for verification

and the improvement of the assembly quality was achieved significantly.