Abstract: With regard to the strong support type of cast-in-place concrete often adopted in loess highway tunnels,the influences of strength,thickness and age of concrete on surrounding rock and lining structure were analyzed by use of numerical imitation technology.The results showed that the influences of concrete strength on the soil and lining were not great,there was rational and economical thickness of the lining,and the age of concrete had large effect on axial force of lining.