Abstract: Statics and modal testing is an important part of space truss structure design. Due to the large size of the space truss structure, the full-scale prototype test is limited by factors such as test site and equipment. Therefore, the scale model test of large space truss structure can not only reduce the test cost and risk, but also provide a new means for the static and modal analysis of space truss structure. The large space truss structure is taken as the research object. Based on the similarity theory, the static similarity relationship and modal response similarity relationship between the space truss prototype and the 1/3 scale model are derived by using the equation analysis method and the dimensional analysis method. Finally, the statics and modal simulation analysis of the prototype truss and the 1/3 scaled model truss are carried out, and the modal test is carried out to verify the correctness of the modal similarity relationship. The results show that it is feasible to predict the static and vibration characteristics of large structural prototypes by similarity theory and model test.