In order to improve the corrosion and wear resistance of mechanical parts, a micro/nano-structured Cr3C2-NiCr ceramic coating was designed and prepared. The Micro/nano-structured Cr3C2 powder was prepared using a planetary ball mill combined with a spray granulator. The Cr3C2 powder and NiCr powder were uniformly mixed, and the micro/nanostructured Cr3C2-NiCr composite coating was prepared on 316L stainless steel by plasma spraying. The corrosion and wear properties of the composite coatings in 3.5wt.% NaCl aqueous solution were investigated by ball-disc reciprocating friction and wear tester combined with an electrochemical workstation. The surface size particles of the composite powder were randomly distributed and the surface structure was compact. The microstructure of the four composite coatings was compact and no obvious pores and cracks were found. The porosity of the WNC3 (nano-Cr3C2 content) composite coating was as low as 0.7%, and the microhardness was 853.26HV0.3. The corrosion degree of the WNC3 coating was the lowest. The average friction coefficient (0.20) and wear rate (9.7×10?7 mm3/(N.m)) of the WNC3 composite coating were the lowest. In conclusion, the addition of 50% nano-Cr3C2 grains can make the interior of the coating more compact, and reduce the porosity and increase the microhardness of the coating. The coating shows excellent corrosion and wear resistance in 3.5wt.%NaCl aqueous solution. Corrosion of the composite coating in 3.5wt.% NaCl aqueous solution will reduce the mechanical properties of the composite coating and increase the wear of the composite coating, while the wear will lead to more defects in the composite coating and increase the possibility of corrosion.