Abstract: To promote the application of steel-basalt fiber composite bars (SBFCB)-reinforced ultra-high performance concrete (UHPC) structures in civil engineering, it is necessary to study the bond performance between SBFCB and UHPC. The pullout tests of eighteen bonding specimens were conducted, and the effects of different bond lengths, bar types and concrete types on the bond performance between SBFCB and UHPC were investigated. The mechanism of bond-slip failure was revealed, and compared with the bond performance between steel bars and concrete. A universal bond stress-slip constitutive model was proposed and the ranges of fitting parameters were provided based on experimental results and existing bond stress-slip models. The results show that with the increase of bond length, the ultimate bond stress decreases due to the uneven distribution of bond stress. Additionally, increasing the bond length can reduce the ultimate slip deformation and improve the corresponding bond stiffness. Compared with steel bars, the ribs of SBFCB are more easily sheared due to their thinner and lower shear strength than those of steel bars, resulting in a greater amount of slip during the pull-out process of the bond between SBFCB and concrete. The steel fibers play an effective bridging role in the tensile cracking process of UHPC, and the bonding performance between SBFCB and UHPC is significantly better than that between SBFCB and NC. The proposed bond stress-slip constitutive model has good adaptability and can be used to analyze the mechanical properties of SBFCB-reinforced concrete structures.