Abstract: In order to study the shear mechanical properties of rock-concrete composite interface, direct shear tests under different normal stresses were carried out on five types of rock-concrete composite interfaces by using RDS-200 rock joint shear test system. The results show that:①The shear stress-shear displacement curves of different types of rock-concrete composite interface roughly exist compaction stage, approximate straight line stage, pre-peak yield stage, post-peak softening stage and residual stage. The post-peak softening stage can be divided into sudden drop type and slow drop type according to different rock types.② For the same type of rock-concrete composite interface, the peak shear strength and residual shear strength increase approximately linearly with the increase of normal stress.③ With the increase of normal stress, the pre-peak shear stiffness of the same type of rock-concrete composite interface increases logarithmically with normal stress. The research conclusions have certain reference significance for the engineering design and protection of rock-concrete composite interface rock mass.