Abstract: With the continuous development of various large-scale projects, the clay-sandstone mixture has been widely concerned by engineering and academic community.At the same time, the loose earth-rock mixture is also the basic material that constitutes the dumping ground of open pit mines and the stability of the dumping site is related to mine production as well as life and property safety.The static side pressure coefficient K0 is an important parameter in geotechnical engineering and is the basis for studying the deformation characteristics and stress state of the clay-sandstone mixture .The clay and sandstone of Antaibao Open-Pit Mine were selected and mixed and the K0 Consolidation Tests under the conditions of consolidation stress of 100,200,500,1 000,2 000 and 4 000 kPa were carried out respectively using GDS triaxial tester in order to study the consolidation deformation characteristics and coefficient K0 of clay-sandstone mixture.The results show that with the increase of consolidation stress, the density of clay-sandstone mixture increases exponentially and the growth rate decreases gradually and the compressibility decreases accordingly; the compressive modulus of clay-sandstone mixture containing 50% of rock is 7.778 MPa, which falls in the medium level compressive soil; and during the increase of consolidation stress, the K0 value decreases first and then stabilizes.