The thin surface layers of 316 L stainless steel with different mass fractions (5%, 10%, 13.26%) and sizes (nano, micro) SiC composite powder are deposited on Q235 steel substrates by laser cladding process. Sections of such coatings are examined to reveal their microstructure and properties and to analyze the strengthen mechanism, by using optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffractometer (XRD). The distribution of the hardness on the cross section of cladding layer and wear resistance of the coatings also are tested by microhardness tester and frictional wear tester. The results show that 316L stainless steel with 10% of the SiC is appropriate. With the same proportion, micro SiC just dissolve partly, but some SiC phase exists; while nano SiC will be dissolved totally, producing new strengthening phase M7C and FeSi, which can effectively inhibit the growth of the columnar crystal, and change the microstructure of the cladding layer for cellular crystal, also restrain the growth of g-CrFeNi grain in the overlapping remelting area, the coating hardness reaches 527HV increase by 132% compare with the pure 316L coating; the coating hardness is higher than 100HV, compare with the cladding layer with the addition of 10% micro SiC, and the friction coefficient and wear weight loss are minimal, which leads excellent wear resistance.