Due to few research on shear behavior of epoxy joints of segmental precast concrete cap beams with key-tooth joints currently,3 groups of 7 full scale specimens with key-tooth joints were designed and produced,and a direct shear experiment was carried out by taking 3 factors of key tooth inclination angle,key tooth depth and lateral compressive stress into account.The test results show that:The failure mode of the key tooth epoxy joint under direct shear load is brittle,and the shape of main crack is influenced by the coupling of lateral com-pressive stress,key tooth depth,and key tooth inclination angle;Increasing the lateral compressive stress or the key tooth depth can effec-tively improve the shear bearing capacity of the key tooth epoxy joint,and the relative sliding at failure state remains at the same level;The cracking load and shear bearing capacity of the key tooth epoxy joint are maximum as the inclination angle of the key teeth is 30 °,and the shear bearing capacity joint will significantly decrease as the inclination angle of the key teeth is greater than 45 °.It is suggested that the inclination angle of the key teeth should not exceed 45 ° in practical engineering.