Objective To improve the erosion wear resistance of fluid mechanical components. Methods NiCr-Cr3C2 coatings were deposited by supersonic plasma spraying system. The phase structure of the powders and coatings were analyzed by XRD. The microstructure and chemical component were observed and analyzed by SEM and EDS. The grain structure was examined by TEM. The porosity was determined by Image J2x porosity calculation software. The microhardness, elastic modulus and bonding strength were also respectively tested by microhardness tester, NANOVEA and universal tensile tester. The erosion test was done by the dynamic load abrasive testing machine, with the erosion Angle at 90°, sands-cement ratio at 5:8, and erosion time 3 h. Results The main phase structure of NiCr-Cr3C2 coatings were NiCr, Cr3C2 and Cr7C3. The grain structure were composed of crystal, nanocrystalline, and transition zones. The microhardness of the coatings was 911HV0.3, about 3 times of the substrate, and the porosity was 1.4%, the bonding strength was 66 MPa, and the elastic modulus was 215.3 GPa. The main erosion mechanism of NiCr-Cr3C2 coatings was fatigue spalling at 90° attack angle. Conclusion The NiCr-Cr3C2 coatings deposited by supersonic plasma spraying system perform good erosion wear resistance.