Abstract: In this paper,a twice-initial-strain-method for nonlinerly rheological FEM of soil has been estab-lished In this theory, the solution of nonlinearly rheological problem is obtained at first by the visco-initial-strain-method in ime domain,then by nonlinearly-elastic-initial-Strain-method in each time step. Finally,in ac-cordance with the rheological behavior of soil,a practical engineering problem of cement-soil-pile in supportingexcavated slope is analyzed with this method.