Abstract: The new technology of anchorage-reinforced in the subgrade widening project of highways is put forward in order to realize the effective connection between the new and the existing subgrades. The anchoring mechanism of anchor bolts and the geogrids-reinforced function mechanism in the joint part between the new and the existing subgrades are analyzed. The design method of anchorage-reinforced composite structure is studied. Based on the FEM, the characteristics of the ground settlement and horizontal displacement, sungrade surface settlement and the geogrid stress are studied according to three subgrade widening schemes, that is, excavation step only, excavation step + geogrid reinforcement, and excavation step + geogrid reinforcement + anchor bolt. The results can be used as a reference for future design of subgrade widening project of highways.