There always exists difference in moving conditions between the real parts and the theoretical parts. So in the process of aircraft design and flight tests, it's necessary to know the real moving condition of the aircraft parts. But there exists many problems in the analysis of the real moving condition by a variety of instruments. In this article, we will take the flap rotation angle measurement for example, to analyze the rotation angle using cycle simulation method and dihedral angle method with the data collected by laser tracker. We will introduce and analyze these two methods in detail, in order to search reasonable method to eliminate the influence of measure error,manufacture error and structure deformation to the final results, which will be used in the following working.