In this study, fiber pullout tests were conducted under varying fiber embedment depths and loading rates to investigate the interfacial bonding properties of glass-sand ultra-high performance cementitious composite (GS-UHPCC). Quantitative analysis was performed on the interfacial bonding properties and mechanical properties of steel fibers and the matrix. Furthermore, the load-slip model of steel fiber was established. The results show that the interfacial bonding properties between steel fiber and GS-UHPCC are significantly improved with the increase of fiber embedment depth. When the fiber embedment depth increases to 12 mm and 18 mm, the pullout peak load of steel fiber increases by 43.81% and 87.56%, respectively, compared with specimen with fiber embedment depth of 6 mm. Similarly, the pullout energy increases by 63.27% and 176.36%, respectively. In addition, the interfacial bonding properties between steel fiber and GS-UHPCC exhibit obvious rate sensitivity. When the loading rate increases from 0.5 mm/min to 5.0 mm/min, the average increases of the pullout peak load and pullout energy of steel fiber are 27.16% and 127.98%, respectively. The load-slip model considering the steel average bonding strength and decayed bonding strength can effectively characterize the interfacial behavior between the steel fibers and the matrix.