Aiming at the poor stability caused by temperature variation of aircraft assembly equipment, the spatial position of assembling equipment at different temperatures was measured considering the factors such as tooling structure design and assembly site environment. Based on statistical analysis of data, the position data of tooling at different temperatures was compared with those at periodic check and thermal expansion deformation of the equipment was obtained. The key factors causing poor measurement stability of the tooling were explored, and the corresponding solutions and control methods were put forward. According to the improved control method proposed in this study, when the temperature change is within 5 ℃ , overall deformation of the assembly tooling can be controlled within the tolerance range required by assembly, verifying effectiveness of the proposed optimization measures for stabilizing measurement of tooling and providing reference basis for measurement accuracy and precision of aircraft assembly tooling.