Concrete structure in the increasing load, long-term physical, chemical and biological effects of different degrees of damage or destruction, a serious impact on the safety and durability of concrete structure. Therefore, in order to evaluate the application of PUHPC material in the repair and strengthening of concrete structures, the three-point bending test of PUHPC-NC bonded specimens under static load is carried out in this paper. The main test parameters are concrete strength. The influence of the strength difference of concrete on the failure pattern, crack propagation behavior and bond strength of bonded specimens is systematically studied. The results show that although the strength of the matrix on both sides is different, the fracture failure of the bonding specimens of PUHPC and NC occurs at the interface The bonding effect between the bonding factor in PUHPC and the exposed aggregate on NC surface is the key to dominate the bonding properties and crack growth characteristics of the interface between the two, the interface bearing capacity and crack growth behavior of PUHPC-NC bonded specimens show different changes.