Provided is a method for preparing an acrylic copolymer, and more specifically, provided are a method for preparing an acrylic copolymer including: i) adding and polymerizing 50 to 80 parts by weight of a methyl (meth)acrylate monomer and 10 to 49 parts by weight of a C2-C12 alkyl (meth)acrylate monomer, based on 100 parts by weight of a total monomer content, in a reactor (S1); and ii) adding and polymerizing 1 to 10 parts by weight of the methyl (meth)acrylate monomer, more than 0.01 part by weight to less than 1 part by weight of an acrylic cross-linking agent, and a surfactant, based on 100 parts by weight of the total monomer content, in which a polymerization conversion ratio of the polymerization in step (S1) is 70% to 90% (S2), an acrylic copolymer prepared therefrom, and a resin composition including the same.