Shape detection is a vital part of aircraft assembly. Traditional measurement method based on analog delivering cannot meet the requirements of shape detection of large structures in aircraft assembly. It is difficult to detect largesize and complex structures with separate digital measurement equipment and methods. Therefore, this paper constructs an automatic scanning system consisting of industrial robot and laser tracker system, and studies the automatic detection methods for large-scale structures in aircraft assembly. According to the results of trajectory planning and simulation, the scanning system realizes measurement on large structures, and compares the measurement results with the theoretical digital model to analyze the error information of large structures and realize the detection of large structures.