The interfacial bonding performance between ultra-high performance concrete(UHPC) permanent template and ordinary concrete (NC) is the key to their synergistic effect. The effects of diffe-rent keyway types, concrete strength, and curing conditions on the interfacial bonding performance of UHPC-NC were studied. The results indicate that keyway can improve the bonding strength of UHPC-NC interface, with B-type keyway mechanical interlocking contributing the most. The strain of the central axis of the interface of the splitting tensile specimen is greater than that of the two sides, and the interface crack expands from the horizontal tensile strain to the compressive strain region. The existence of keyways in composite specimens causes cracks to extend from one end to the other inside the concrete, rather than developing inward from both ends. As the compressive strength of post poured concrete increases, the increase rate of the interfacial splitting tensile strength decreases. Steam curing specimens result in a larger initial shrinkage deformation and a larger stress concentration area than standard curing specimens. The interfacial splitting tensile strength of composite specimens can be calculated from the compressive strength of concrete cubes and the fitting parameter c. The optimal permanent template keyway parameters and maintenance conditions are proposed.