In the dam heightening project, the bonding quality of the new and old concrete is directly related to the stability and safety of the entire dam structure. The concrete oblique shear test can simulate the oblique shear forces experienced by the bonding interface between new and old concrete with reinforcement anchoring under actual working conditions. In this paper, the influence of planting depth, planting ratio and planting method on the oblique shear performance of new and old concrete bonded specimens is analyzed by conducting oblique shear tests on new and old concrete bonded specimens. The results show that the failure of the non-planted reinforcement specimen is brittle failure, and the failure of the planted reinforcement specimen is ductile failure. The oblique shear strength of the specimen increases with the increase of the planting reinforcement rate and planting depth. The relationship between the oblique shear strength of the specimen under the four planting reinforcement methods is as follows: The inverted triangle arrangement> the upper and lower arrangement> the regular triangle arrangement> the horizontal arrangement. The oblique shear strength of the horizontal and inverted triangle reinforcement planting methods is 73.38% and 210.24% higher than that of the non-planting reinforcement specimens, respectively. By integrating the friction shear theory with the calculation formula of oblique cross-sectional bearing capacity, the calculation model of the bonded oblique shear capacity of new and old concrete anchored by planting reinforcement is obtained, which provides a theoretical reference for evaluating the bonded oblique shear strength of new and old concrete under various reinforcing bar anchoring conditions.