To investigate the interfacial shear performance between ultra-high performance concrete (UHPC) and normal concrete (NC), 13 UHPC-NC direct shear specimens were designed and fabricated. Through push out tests, the influence of UHPC rib width, height, and spacing on the interfacial failure mode and shear bearing capacity were discussed. Furthermore, a finite element model of the UHPC-NC specimens was established using ABAQUS, and parameter analysis was conducted. The results indicate that the failure modes of the ribbed UHPC-NC interface mainly include: complete interface failure and UHPC ribs sheared off; partial interface failure and partial failure of NC embedded between UHPC ribs; partial interface failure and complete failure of NC embedded between UHPC ribs. The specimens with rib widths of 10 mm primarily exhibit the first failure mode, while specimens with rib widthsof 15 mm and 20 mm correspond to the latter two failure modes. Additionally, as a whole, the shear capacity and slip of the interface gradually increase with the increase of rib width and spacing, demonstrating better ductility. When the rib width is 20 mm, increasing the rib height helps to improve the interface load-carrying capacity. However, as the rib height increases, the effectiveness of load enhancement significantly decreases.