The work aims to study the effect of interfacial slip at the inlet step/outlet land on the oil film thickness and coefficient of friction (COF) of the step bearing. The oil film thickness and coefficient of friction were solved by establishing a one-dimensional step slider model taking account of interfacial slip at the inlet step and outlet land. At the same time, fluorinated diamond-like carbon (F-DLC) coatings were prepared on the contact surface of the step slider, and the effect of F-DLC coatings on the lubrication performance was studied under the condition of parallel contact gap and compared with the results of theoretical calculation. The theoretical results showed that when the interfacial slip occurred only at the inlet step, the oil film thickness increased and the COF decreased with the interfacial slip increasing. When the interfacial slip only occurred at the outlet land, with the increase of the interfacial slip, both the oil film thickness and the COF decreased. When the interfacial slip occurred on both the inlet step and the outlet land, there were two results:the oil film thickness and the COF decreased at the same time or the oil film thickness increased and the COF decreased. The experimental results showed that the step slider coated with F-DLC had the maximum film thickness and the minimum COF at the same time, which was opposite to the uncoated step slider. This unique phenomenon was due to the different interfacial slip at the inlet step and outlet land of the step slider caused by the synergistic effect of the micro-convex structure formed by laser processing in the inlet step and the F-DLC coating. The interfacial slip at the inlet step was larger, leading to an increase in film thickness. And at the same time, the existence of interfacial slip made the COF decrease. Under the influence of the inlet/outlet interface slip on the step sliding block bearing, there are two results. The relationship between the interfacial slip ratio at the inlet step and outlet land that can satisfy the commands what can make the carrying capacity and the COF increase synchronously is obtained. The study shows it is experimentally verified that the oil film thickness increases and the COF decreases under certain slippage conditions.