Large aircraft components are generally assembled by multi-material and multi-size components according to a certain process. The temperature change in the large-size assembly space will cause large and inconsistent thermal deformation of components during assembly, which will further affect the assembly coordination accuracy of aircraft products. Based on the requirement of high-precision assembly of large-scale composite components of aircraft in a million cubic meters of global working space, the influence of temperature change on the thermal deformation of tooling and products in different material combinations was studied. Taking the assembly of a typical composite wing box component of a 5-meter class aircraft as the analysis object, the results show that when the temperature changes by 5 ℃, the assembly coordination accuracy will be affected by about 0.1 ~ 0.2 mm. Therefore, in the process of assembly process design, it is necessary to consider the compensation problem of thermal deformation error of product assembly caused by temperature change of 5 ℃, which is of great significance to improve the coordination accuracy of aircraft assembly.