In order to study the shear mechanical properties of regular tooth-shaped joints, the RDS-200 rock joint shear test system was used to conduct direct shear tests on regular tooth-shaped rock-like material joints with 5 types of undulating angles under various normal stress. The results show that:(1) The shear stress-shear displacement curves of regular tooth-shaped joints with different undulating angles generally have compaction stage, approximate straight line stage, pre-peak yield stage, post-peak softening stage and residual stage, there are three modes of slip wear failure, slope gnawing failure and serrated complete shear failure in the shear failure of tooth-shaped joints. (2) Based on the concept of effective undulating angle, an empirical formula for the peak shear strength of regular tooth-shaped joints is proposed, with an average relative error of only 2.9%. (3) As the tooth-shaped asperity undulation angle increases, the peak shear strength, pre-peak shear stiffness, debris quality, and the proportion of shear failure area of the rock joints all increase overall. The research conclusion has certain reference significance for the engineering design and protection of regular tooth-shaped jointed rock masses.