Preparation method of storage-stable compound modified asphalt

The invention relates to a preparation method of storage-stable compound modified asphalt. The preparation method of the storage-stable compound modified asphalt is characterized by comprising the following steps of: 1, adding 5-50% by weight of SBS (Styrene Butadiene Styrene) powder and 50-95% by weight of rubber powder into an extruder and carrying out water cooling, granulating and drying or roll cooling of a roller and slice forming on the reaction product to obtain a solid-state SBS/rubber powder blend; and 2, adding 0-5% by weight of an SBS thermoplastic elastomer into 72.5-90.5% by weight of matrix asphalt, shearing by utilizing a dispersion machine at the temperature of 130-170 DEG C, adding 1-20% by weight of SBS/rubber powder blend, 3-5% by weight of a compatilizer and 0.5-1.5% by weight of a stabilizer, stirring and mixing for 3-5 hours at the temperature of 175-185 DEG C, thereby obtaining the storage-stable compound modified asphalt. The compound modified asphalt prepared by adopting the method has the advantages of good stability and dispersity, difficult sedimentation, better high temperature and low temperature performances and good storage stability.