The invention discloses a bituminous mixture modifier and a preparation method thereof. The bituminous mixture modifier is prepared from waste
polyethylene, waste
polypropylene, a
toughening agent, aninitiator, a modifier, an anti-
ageing agent, filler and
pigment. According to the bituminous mixture modifier and the preparation method thereof, by adopting modification technologies of blending,
grafting,
toughening and the like, the industrial, agricultural and domestic recovered waste PE and PP, the other modifier, the filler and the like are mixed evenly according to a certain ratio to prepare black
solid particles, according to 0.3-0.5% of total
mass of a bituminous mixture, the black
solid particles,
pitch and mineral aggregate are stirred and mixed evenly at a mixing
station under technology conditions of certain temperature, mixing time and the like, thus paving can be conducted, the
rut resistance capability of a bituminous pavement can be greatly improved, and meanwhile, both the
moisture damage resistance performance and the low
temperature resistance performance are obviously improved. By adopting the modification technologies, not only is the cost reduced, but also the high temperature stability of the bituminous mixture can be greatly improved, the
foreign technology monopoly is broken, and the bituminous mixture modifier and the preparation method thereof have profound significance in the aspects of positively responding to national
waste material resource recycling and the like.