The invention discloses C70-TiC reinforced high-quality stainless steel and a preparation method thereof, and belongs to the technical field of alloy material manufacturing. The problems of poor wearresistance and insufficient corrosion resistance of existing austenitic stainless steel are solved. The stainless steel is composed of, by mass, 18%-22% of Cr, 8%-12% of Ni, 1%-1.5% of N, 3%-5% TiC, 0.3%-1.2% C70, and the balance being Fe and unavoidable impurities. After ball milling of Cr powder, Ni powder, ferrochrome nitride powder, TiC, C70 and iron powder, cold pressing for blocks, hot pressing sintering, repeated heating and temperature reduction, and deformation treatment are carried out to obtain the stainless steel. The stainless steel of an ultra-fine structure has high hardness, high ductility and toughness, high wear resistance and excellent corrosion resistance, and can be used in special environments such as a plastic injection molding industry and a food industry.