Research conclusions:Based on the research on the ground cracks and surrounding rock pressure during the excavation of loess tunne,l the dividing line ofdeep and shallow submersion, computingmethod of surrounding rock pressure and designing principle ofsecondary lining of large sectional loess tunnelon Zhengzhou-Xia' n PassengerDedicated Line are presented. The dividingheightofdeep and shallow submersion of loess tunnelon Zhengzhou-Xia' n PassengerDedicated Line is40~60m, the loess tunnel load under shallow-buried condition can be calculatedwithXie Jiaxiu Formula, the loess tunnel load under deep-buried condition can be calculated with TerzaghiTheory and the thickness of secondary lining of loess tunnels under differentburied depth can be the same.