Abstract: Establishing an accurate and reliable surrogate model is one of the key links in digital twin technology. In order to study the method for constructing the dynamic surrogate model in space structural dynamics, a simplified wing structure was selected as the research object. The displacement and acceleration responses of the structure under transient dynamic analysis were obtained by single point sinusoidal constant frequency excitation and full field acceleration sweep frequency excitation, respectively. Taking the time and the response results of some nodes as inputs, and the response values at the concerned nodes as outputs, back propagation (BP) neural network was used to build a dynamic surrogate model. The dynamic surrogate model of the wing structure under transient dynamics was deemed to have been constructed after the established model’s accuracy met the requirement. The model constructed by this method can not only be used to quickly predict the displacement and acceleration responses of multiple nodes, but also lay a foundation for the subsequent construction for dynamic digital twins of space complex structures.