Research conclusions:The three -step temporary inverted arch method can be adopted to the single -track railway tunne,l with strictcontrolof the step lengthsof the step, inverted arch and secondary lining after installation of sectional concrete inverted arch on the top step forgetting the perfectcontrol effec.t The appropriate deformation quantity should be remained in advance to the large deformation tunnel according to themonitored andmeasured data. This is essential to preventof the support's damage in early -stage, the protected arch 's crack in later -stage and the control of construction cos.t The tunnel deformation is restrained to some extent after grouting through the back of the primary supportwalland improvementsof the type ofsteel frame, the form and location of the jointand installation of the vertical connection. The long step construction orkerve has to be forbidden during construction.