A type of wear resistance coating material composed by ternary-boride-based (TBB) cermet coating and steel 65Mn substrate has been developed successfully by in-situ reaction synthesis. The TBB cermet coating has been formed by the in-situ reactions among the mixed raw metal powders during the process of casting. Microstructure has been studied using X-Ray Diffraction (XRD) and scanning electron microscopy (SEM). Results show that the main composition of the coating is ternary boride base hard phase Mo2FeB2 and ferrous base binder phase α-Fe, both of them distribute uniformly in the coating. There is element diffusion in the interface of coating and steel substrate. The bonding at the interface of coating and steel substrate is excellent which has been confirmed by the three-point bend tests.