The invention provides an SBS modified asphalt stabilizer. The SBS modified asphalt stabilizer comprises the following components in parts by weight: 60 to 80 parts of sulfur, 5 to 10 parts of an accelerant, 5 to 10 parts of zinc oxide, 0 to 10 parts of an antioxidant, and 10 to 40 parts of a filling dispersant, wherein the sulfur is a sulfur byproduct obtained by treating catalytic cracking acidgas in a refinery plant, the content of S in the sulfur is greater than 99.0%, the balance is impurities of a desulfurization solution, and the impurities of the desulfurization solution are one or more of sodium sulfate, sodium sulfite, sodium carbonate and sodium bicarbonate. According to the invention, the ductility index and the anti-aging ability of the SBS modified asphalt after aging can beimproved, the development time of the product can be shortened, and the attenuation of the ductility index along with time can be effectively inhibited. In addition, the stabilizer can effectively improve the mechanical properties of the SBS modified asphalt.The invention also provides the SBS modified asphalt.