Impact modifier is an acrylic impact modifier with a "core shell" structure. Its core is a lightly cross-linked acrylic copolymer, and its shell is a methacrylate copolymer, which has good compatibility with PVC. When subjected to external impact, the rubber core undergoes changes, triggering the generation of silver lines and shear bands, absorbing impact energy, and exhibiting excellent impact resistance, weather resistance, and color durability under long-term outdoor exposure conditions.