As an important control index of expressway subgrade, resilient modulus is often based on the static characteristics in the current design method, which is inconsistent with the actual situation. It is of great significance to establish the control method of resilient modulus of subgrade based on the dynamic characteristics of subgrade for the construction of expressway with high quality and good road performance. In this paper, the dynamic deformation characteristics of highway subgrade are studied through laboratory tests and finite element simulation. The variation law of dynamic deformation of subgrade structure with loading times is analyzed, and the relationship between dynamic deformation of subgrade and resilient modulus of subgrade is established. From the point of view of dynamic deformation, the requirement of resilient modulus of expressway subgrade is put forward. The research results may provide guidance for the control standard of resilient modulus of expressway subgrade.