In order to study the influence of roughness on the shear mechanical properties of granite concrete specimens, the splitting method was first used to obtain the granite structural planes, and the joint roughness coefficient JRC was obtained by scanning with a laser three-dimensional profilometer. Concrete was poured on the structural planes to make rock-concrete bonding specimens, and then shear tests were conducted and acoustic emission monitoring was carried out simultaneously. The results of the shear test show that the shear stress-strain curves of granite concrete bonded specimens with different roughness have a roughly consistent trend, and the shear failure modes of the specimens are different. As the roughness increases, the shear softening characteristics of the specimen become increasingly apparent, and the peak shear strength gradually increases. The synchronous acoustic emission monitoring during the shearing process shows that the acoustic emission energy and ringing count both increase with the increase of roughness, while the acoustic emission characteristic b value decreases with the increase of roughness. The research results of this article can provide a reference for revealing the shear failure behavior of granite concrete interface in engineering.