It remains a popular question whether rare earth oxides encourage reinforcing phases to the uniform distribution in cermet coating to improve the mechanical properties. This study applied laser cladding to prepare the TiAl/WC/CeOsub.2 MMC cermet coatings on the TC21 alloy substrate. The effects of CeOsub.2 content on the phase composition, microstructure formation, evolution mechanism, and properties of cermet coatings were investigated. Results show that the incorporation of CeOsub.2 did not change the phase of composite coating, but the shape of the TiC phase has a close relation to the CeOsub.2 content. CeOsub.2 enhanced the fluidity of the molten pool, which further encouraged the TiC/Tisub.2AlC core-shell reinforcement phase. With the increase in CeOsub.2 content, the optimized coating contributed to homogenous microstructure distribution and fine grain size. Owing to the hard phases strengthening and dispersion strengthening effects of CeOsub.2, the microhardness of the composite coatings was all significantly higher (almost 1.6 times) than that of the substrate. Importantly, the addition of CeOsub.2 significantly improved the wear resistance of the composite coating. This work provides a certain reference value for the study of surface strengthening of key parts in the aerospace field.