The failure characteristic of geomatertials in different stress states is analyzed, and it is found that the stability of geotechnical structure depends on not only shear strength index c and tanφ, but also tensile strength index T. The overvalued of tensile strength of materials could lead to non-conservative results in the primary strength reduction method. Therefore, the FEM strength reduction method should take identical reduction of both tensile strength index and shear strength index into account. In other word, tension and shear strength reduction method (TSSR) in the process of strength reduction should be adopted. The necessity and correctness of TSSR is validated by stimulating four typical example models, i.e. the general slope, the stalactite, the tunnel and the steep slope. Studies show that the modified strength reduction method has universal applicability in geotechnical engineering.