According to the current common methods of flight load modeling, based on the exhaustive method and genetic algorithm, the comprehensive influence of bridge index and load equation index on the load model is considered, and an optimized flight load modeling method is proposed for the complex structure aircraft (taking the multi-beam and multi-wall structure as an example), and the error comparison between the optimized method and the traditional method is carried out. This method can satisfy both simple and complex structure flight load modeling methods. The ground load calibration test data of an aircraft wing are used to establish the load equation, and the comparison with the traditional method proves that the shear equation established by the optimized method has higher accuracy and iterative stability, and the bending moment equation errors of the two methods are similar and meet the requirements. The results of applying this method to measure the flight load of each measurement profile of the wing show that the model obtained by this method is accurate and reliable, and can be used for flight load measurement and safety monitoring.