There are many experimental studies on the bonding interface between ultra-high performance concrete (UHPC) and normal concrete (NC). However, there are still few researches on how to effectively simulate and analyze the relevant parameters in the finite element software. The large-scale finite element analysis software ABAQUS is used to establish a finite element model to simulate the bonding interface between UHPC and NC by the cohesion element. And the bonding properties of UHPC-NC interface at the different levels of interface roughness are analyzed by modifying the parameters of the cohesion model. The finite element models of direct shear and oblique shear tests are established, and the interfacial friction coefficient is deduced by using the Mohr Coulomb theory. The results show that the simulation of UHPC-NC interface by cohesion element can well reflect the actual mechanical performance.