For the tunnel general sections, seismic damage types appeared in Wenchuan earthquake. In order to improve aseismatic performance of tunnel general sections in high intensity earthquake area, by analyzing the seismic survey data of general sections of highway tunnel in Wenchuan earthquake, seismic damage analysis is concluded. The results show that the seismic damages of tunnel general sections occurred mainly in the soft rock of uniform section, the soft rock part of soft and hard surrounding rock and the defect section. Through three-dimensional finite difference numerical simulation and analysis of typical field damage, seismic damage mechanism of highway tunnel general section is studied. The seismic damage mechanism of surrounding rock uniform general section is understood; namely there is almost no seismic damage in the hard rock tunnel general section damage, while the seismic damage is more serious in the soft rock tunnel general section; lining structure is greatly influenced by the seismic inertia force, and forced displacement comes second. The seismic damage mechanism of the soft and hard surrounding rock general section is revealed, that is, the seismic damage occurs mainly in the soft rock part of soft and hard surrounding rock; the main influence factor is the forced displacement, closely followed by seismic inertia force. The seismic damage mechanism of the defect of general section is disclosed, namely the seismic damage is mainly caused by the seismic inertia force, and forced displacement has little effect. These research results can provide reference for the seismic fortification of highway tunnel general section in high intensity earthquake area.