In situ laser cladding coating with γ′-Ni3Al strengthening phase is fabricated by controlling the Al and Mo contents in Ni-based self-fluxing alloy powder on H13 die steel surface. The microstructure and phase structure of the four kinds of chemical composition powder are analyzed by means of optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffractometry (XRD). The results indicate that the macroscopic morphologies of the four kinds of laser cladding coatings are smooth, dense and without obvious macroscopic defects. Ni-based self-fluxing alloy powder with Al added is easier to generate -Ni3Al phase. When the Al content reaches a certain degree, β-NiAl phase is found in the coating. Fe mainly exists as (Fe, Cr) solid solution, while the (Ni, Cr) phase is small. The β-NiAl phase is almost not found when Mo is added in the coating. When the Al content is small, Mo and Fe combining to form Mo-Fe are intermetallic compound. But when β-NiAl phase is generated in the coating as the Al content increases, Mo and Al combine to form AlMo3. The existence of Mo-Fe intermetallic compound makes (Fe, Cr) solid solution less than that of the same Al content without Mo, but the (Ni, Cr) solid solution is more than without Al. The friction coefficients of all cladding coating samples are lower than the H13 steel substrate. The highest microhardness of the coating increases by 3.3 times and the wear resistance increases by 3.8 times, respectively, in comparison with the substrate.