Abstract：Due to the four-lane highway tunnel having super-span and flat-section，together with the influence of different processes and the multiple disturbance of surrounding rock in period of construction，the dynamic construction mechanics of tunnel is extremely complicated，the surrounding rock is very easy to lose stability and collapse occurs. By using the“CTSSSRH”and finite element analysis，physical model test and numerical simulation are carried out to research the distribution and the developing law of displacement，stress，strain and failure zone on surrounding rock and structure of the tunnel. The results that the settlement on crown is much greater than the horizontal displacement，so the settlement can be used as the index of surrounding rock stability. In addition，for the case of rock extrusion，the maximum principal stress of side wall is tensile stress，and the axial force of bolt is greater than other bolt. Some dynamic construction mechanics rules in varying construction method are obtained，and the reasonable construction method of four-lane highway tunnel is put forward.
