Aiming at the problems that it was difficult to determine the load boundary conditions of mechanical structures under complex working conditions, an external load inversion technology was proposed based on multi=information fusion of simulation and measurement. Firstly, the finite element model of the structures to be studied was established, the unit load was applied at the positions of the external load, and the full field strain response of the member was calculated. Then, the optimal layout scheme of measured points and the optimal load coefficient matrix of strain test were obtained based on the D-optimal design principle, and the dynamic response relationship between external load and strain was established...