Waterproof composite modified asphalt and preparation method thereof

The invention relates to the technical field of asphalt, and particularly discloses waterproof composite modified asphalt and a preparation method thereof. The waterproof composite modified asphalt comprises the following raw materials in parts by weight: 60-90 parts of a waterproof asphalt matrix; 6 to 10 parts of an SBS material; 3-7 parts of an anti-aging material; the anti-aging material comprises N-4 (anilinophenyl) maleimide, a coupling agent and functional particles, wherein the functional particles comprise silicon dioxide and cerium oxide; the preparation method comprises the following steps: S1, primary mixing: mixing and stirring the SBS material and the anti-aging material according to a formula to obtain a primary mixture; s2, blending: after preparing initial hot asphalt, adding the initial mixture into the initial mixed asphalt, and stirring to obtain the waterproof composite modified asphalt. According to the waterproof composite modified asphalt, the ageing resistance of the composite asphalt