A polyimide-based block copolymer comprising a first repeating unit represented by Chemical Formula 1, and a second repeating unit represented by Chemical Formula 2: wherein, in Chemical Formulae 1 and 2, each R 1 is the same as or different from each other in each repeating unit, and each is independently a single bond, -O-, -S-, -C(=O)-, -CH -, -S(=O) 2 -,-Si(CH 3) 2 -, -(CH 2) p - (wherein 1≤p≤10), -(CF 2) q - (wherein 1≤q≤10), -C(CH 3) 2 -, -C(CF 3) 2 -, -C(=O)NH-, or a C6 to C30 aromatic organic group; each R 2 is independently -H, -F, -Cl, -Br, -I, -CF 3, -CCl 3, -CBr 3, -Cl 3, -NO 2,-CN, -COCH 3, -CO 2 C 2 H 5, a silyl group containing three C1 to C10 aliphatic organic groups, a C1 to C10 aliphatic organic group, or a C6 to C20 aromatic organic group; n1 and n2 are independently 0 to 3; Ar 1 and Ar 2 are the same as or different from each other in each repeating unit, and each is independently a C6 to C30 aromatic organic group, at least one of Ar 1 and Ar 2 comprises a C6 to C30 aromatic organic group substituted with -OH,-COOH, -CN, acrylate, or methacrylate, and the aromatic organic group exists alone, or two or more aromatic organic groups are bonded to each other to form a condensed ring, or two or more aromatic organic groups are linked by a single bond, -O-, -S-, -C(=O)-, -CH -, -S(=O) 2 -, -Si(CH 3) 2 -, -(CH 2) p- (wherein 1≤p≤10), -(CF 2) q -(wherein 1≤q≤10), -C(CH 3) 2 -, -C(CF 3) 2 -, or -C(=O)NH-; E 1 to E 6 are independently a single bond, -NH-, or -C(=O)-; each Z 1 is the same as or different from each other in each repeating unit, and each is independently a trivalent linking group derived from at least one compound selected from the group consisting of triacyl halide, triamine, and tricarboxylic acid; and each Z 2 is the same as or different from each other in each repeating unit, and each is independently a divalent linking group derived from at least one compound selected from the group consisting of diacyl halide, diamine, and dicarboxylic acid. each R 1 is the same as or different from each other in each repeating unit, and each is independently a single bond, -O-, -S-, -C(=O)-, -CH -, -S(=O) 2 -,-Si(CH 3) 2 -, -(CH 2) p - (wherein 1≤p≤10), -(CF 2) q - (wherein 1≤q≤10), -C(CH 3) 2 -, -C(CF 3) 2 -, -C(=O)NH-, or a C6 to C30 aromatic organic group; each R 2 is independently -H, -F, -Cl, -Br, -I, -CF 3, -CCl 3, -CBr 3, -Cl 3, -NO 2,-CN, -COCH 3, -CO 2 C 2 H 5, a silyl group containing three C1 to C10 aliphatic organic groups, a C1 to C10 aliphatic organic group, or a C6 to C20 aromatic organic group; n1 and n2 are independently 0 to 3; Ar 1 and Ar 2 are the same as or different from each other in each repeating unit, and each is independently a C6 to C30 aromatic organic group, at least one of Ar 1 and Ar 2 comprises a C6 to C30 aromatic organic group substituted with -OH,-COOH, -CN, acrylate, or methacrylate, and the aromatic organic group exists alone, or two or more aromatic organic groups are bonded to each other to form a condensed ring, or two or more aromatic organic groups are linked by a single bond, -O-, -S-, -C(=O)-, -CH -, -S(=O) 2 -, -Si(CH 3) 2 -, -(CH 2) p- (wherein 1≤p≤10), -(CF 2) q -(wherein 1≤q≤10), -C(CH 3) 2 -, -C(CF 3) 2 -, or -C(=O)NH-; E 1 to E 6 are independently a single bond, -NH-, or -C(=O)-; each Z 1 is the same as or different from each other in each repeating unit, and each is independently a trivalent linking group derived from at least one compound selected from the group consisting of triacyl halide, triamine, and tricarboxylic acid; and each Z 2 is the same as or different from each other in each repeating unit, and each is independently a divalent linking group derived from at least one compound selected from the group consisting of diacyl halide, diamine, and dicarboxylic acid.