In this paper, the shear performance of an NC-UHPC (ultra-high performance concrete) composite structure is studied, which is mainly used for small and medium-span bridges. Based on the overview of the existing completed bridges and the structural form of shear keys, four groups of experiments were completed consisting of UHPC bridge deck, ordinary concrete bridge deck and UHPC filling notch, and four groups of experiments were carried out according to the different diameters of the steel bars to explore the effects of the ultimate shear bearing capacity, steel bar diameter and number of steel bars on the shear performance of shear bonds. The test results show that under the action of concentrated load, the NC-UHPC composite structure undergoes flexural and shear failure. The bearing capacity, stiffness and ductility of the NC-UHPC composite structure are better than those of traditional PBL shear keys and stud shear bonds. Based on ABAQUS software, a refined finite element model of the shear bond of NC-UHPC composite structure was established, and the prediction results of the model were in good agreement with the load-displacement curve obtained by the experiment, and the finite element model was further used to carry out parameter analysis.