Under the deterministic assembly mode of aircraft structures， coaxiality deviations occur at the connecting holes of parts during assembly due to factors such as hole-making deviations and shape deviations. When these deviations are relatively large， they cause local assembly stress and weaken the mechanical properties of the structure.For the deterministic assembly of aircraft fuselage structures， this study combines the Jacobian-torsor method with the influence coefficient method to determine the matrix expressions of part shape deviations， final hole positioning deviations， and temporary fastener connections. It also proposes a coaxiality deviation calculation model that accounts for deviation accumulation and part deformation， while establishing an assembly experimental system for coaxiality deviation.By comparing the measured deviation data， the calculation results of the Jacobian-torsor model and those of the proposed model， it is found that the average error between the proposed model and the measured data is reduced by 8.89%. This improves the deviation calculation accuracy of the fuselage structure under the deterministic assembly mode and provides a more reliable theoretical basis for the optimization of assembly processes.