The invention discloses a preparation method of an environment-friendly type composite modified
asphalt. The preparation method comprises three steps including quick dissolving rubber master batch preparation, quick dissolving rubber
mother liquor preparation, and co-crosslinking growth with SBS. The preparation method comprises following specific steps: 1, quick dissolving rubber master batch preparation, wherein tyre rubber
powder is subjected to multi-stage screw continuous desulphurization technology for desulphurization, and is subjected to screw
extrusion and
granulation so as to obtainthe quick dissolving rubber master batch; 2, quick dissolving rubber
mother liquor preparation, wherein the quick dissolving rubber master batch and matrix
asphalt are mixed at a
mass ratio of 32 / 68-65 / 35, immersion growth is carried out, and shearing using a high speed shearing equipment is carried out so as to obtain the quick dissolving rubber
mother liquor; and 3, co-crosslinking growth, wherein the quick dissolving rubber mother liquor and SBS modifying agent are mixed, a co-crosslinking stabilizing agent is added into an obtained mixed product, and stirring growth is carried out so as toobtain the environment-friendly type composite modified
asphalt finished product. The preparation method is capable of realizing recycling of a large amount of waste tyre, and is excellent in environment protection performance; the produced finished product possesses both high and low temperature performance, is excellent in middle temperature antifatigue performance, and
noise reduction performance, and high in
ultraviolet ray resistant intensity; deformation degree is low; and the
hardness is larger.