According to the construction conditions of Kuiqi No.2 small-space tunnel with super-large cross-section and eight traffic lanes in the second phase project of Fuzhou International Airport Highway

a discrete element analysis program is established to simulate the construction process. In the program

the double-heading construction method

CRD method and CD method have been simulated. The settlements of vault

horizontal deformations of middle rock pillar

horizontal deformations of surrounding rock and plastic zone of surrounding rock are analyzed and the advantages of the three methods are compared. Considering the characteristics of Kuiqi No.2 Tunnel

the practical construction scheme is optimized. The double-heading method is changed to CRD method at the tunnel entrance. The modification of construction method has great contribution to cut down the cost and to reduce erection time. The results provide some reasonable references to design and construction for similar engineering.