Based on continuum damage theory and statistical strength theory,this paper presents a statistical damage constitutive model reflecting the full process of rock failure,in the fundamental equations of which the characteristic parameters of complete stress-strain curves of rock failure are introduced and the geometrical characteristics of the curves are considered also,so as to solve the difficulties in resolving the parameters of the constitutive equation by traditional method and increase the precision of solutions.Finally,based on the results obtained by triaxial compression test of sandstone from some side slope,this article validates the established statistical damage constitutive model for rock is reasonable.