The bilayer porous material with dense substrate layer and variable porosity surface layer was prepared by powder metallurgy technology. TiH₂ was used as the pore former to improve the oil content in the surface layer, and amide wax was used as a dense agent to increase the density and strength of the substrate. The microstructure, phases distribution and the worn surface morphology were characterized by SEM, EDS, XRD, etc. The tribological properties under boundary lubrication conditions were tested by end-face friction tester. The self-lubricating mechanism of single and bilayer sintered materials under different load conditions was analyzed by comparing their friction coefficients under the progressive loading friction test. Results show that adding TiH₂ in the surface layer can effectively improve the porosity and oil ratio of the bilayer materials. Meanwhile, the hard particles TiC generated by the in-situ synthesis reaction have a hard reinforcing effect on the pore channel, which will improve the wear resistance and maintain steady the contact interface and lubrication state of the friction pair. The composite material containing 3.5%TiH₂ has better mechanical and tribological properties. The looser surface layer of the composite material has a better oil self-lubricating property, and the dense substrate can effectively prevent the oil moving downward and keep the lubricant between the friction surfaces. So the comprehensive tribological and mechanical properties of the composite material are better than that of the single-layer material, which is suitable for heavy load or complex lubrication conditions.