Self-locked anchor is a new type of underreamed anchor, and which is more and more frequently used in both new construction and structural retrofitting or strengthening projects. Nevertheless, current design codes do not contain suitable design recommendations for these anchors. This study investigates the anchorage mechanisms of self-locked anchor under combined tension and shear loadings. The experimental parameters mainly include anchor diameters (Φ16 and Φ20) and loading angles (0°, 30°, 45°, and 60°). The present results indicate the characters of axial and transverse deformations, the ultimate bearing capacity, the fracture pattern of anchor, and the breakout model of concrete.