By finite element method，the courses of dynamic construction of multiple-arch tunnels with eight traffic lanes and surrounding rocks of class IV and V are simulated；the excavation effects of two construction methods，which are the double-side-drift method and the CRD method，are compared based on the displacements of surrounding rock mass and preliminary lining and the second lining. Through comparing the numerical calculation results of stresses and displacements in surrounding rock，it can be concluded that the double-side-drift method has advantages in coupling the surrounding rock and the preliminary lining into full play of supporting the tunnel，which will benefit the second lining with certain safety margin. The CRD method is of advantages in horizontal displacement control，but it is not as effective as the double-side-drift method in vertical displacement control at the tunnel top according to the numerical calculation of multiple-arch tunnel with eight traffic lanes. It can be concluded that from overall analysis，the double-side-drift method is more suitable than the CRD method in multiple-arch tunnel with eight traffic lanes.