An anti-coking nanomaterial based on a stainless steel surface. In percentage by weight, the nanomaterial comprises: 0 to 3% of carbon, 23% to 38% of oxygen, 38% to 53% of chromium, 10% to 35% of ferrum, 0 to 2% of molybdenum, 0 to 4% of nickel, 3.5 to 5% of silicon, 0 to 1% of calcium, and the balance of impurity elements. Also disclosed are a preparation method for the anti-coking nanomaterial, the anti-coking nanomaterial that is based on a stainless steel surface and that is prepared by using the preparation method, and a stainless steel substrate comprising the anti-coking nanocrystalline material.