A method for manufacturing a water-treatment membrane, the method comprising: preparing a porous support; and forming a polyamide active layer on the porous support by interfacial polymerizing a composition for interfacial polymerizing polyamide and an acyl halide compound, the composition for interfacial polymerizing polyamide comprising: an amine compound; a chain-type-structured additive containing one or more amino groups and two or more hydroxyl groups bonding to a carbon atom; and a surfactant, wherein a content of the amine compound is from 0.001 wt% to 10 wt% based on 100 wt% of the composition for interfacial polymerizing polyamide, a content of the additive is from 0.01 wt% to 1 wt% based on 100 wt% of the composition for interfacial polymerizing polyamide, a content of the surfactant is from 0.005 wt% to 0.5 wt% based on 100 wt% of the composition for interfacial polymerizing polyamide, the 'chain-type structure' means a structure that does not include a ring, the polyamide active layer has a number of hydroxyl groups, the amine compound is m-phenylenediamine (mPD), p-phenylenediamine, 1,3,6-benzenetriamine, 4-chloro-1,3-phenylenediamine, 6-chloro-1,3-phenylenediamine, 3-chloro-1,4-phenylenediamine or a mixture thereof, the acyl halide compound is trimesoyl chloride, isophthaloyl chloride, terephthaloyl chloride, or a mixture of two or more types thereof, and the additive is represented by the following Chemical Formula 1 or 2: in Chemical Formulae 1 and 2, m and n1 to n3 are an integer of 1 to 10; and X1 to X3 are each a hydroxyl group; or an alkyl group, and at least two of X1 to X3 are a hydroxyl group. preparing a porous support; and forming a polyamide active layer on the porous support by interfacial polymerizing a composition for interfacial polymerizing polyamide and an acyl halide compound, the composition for interfacial polymerizing polyamide comprising: an amine compound; a chain-type-structured additive containing one or more amino groups and two or more hydroxyl groups bonding to a carbon atom; and a surfactant, wherein a content of the amine compound is from 0.001 wt% to 10 wt% based on 100 wt% of the composition for interfacial polymerizing polyamide, a content of the additive is from 0.01 wt% to 1 wt% based on 100 wt% of the composition for interfacial polymerizing polyamide, a content of the surfactant is from 0.005 wt% to 0.5 wt% based on 100 wt% of the composition for interfacial polymerizing polyamide, the 'chain-type structure' means a structure that does not include a ring, the polyamide active layer has a number of hydroxyl groups, the amine compound is m-phenylenediamine (mPD), p-phenylenediamine, 1,3,6-benzenetriamine, 4-chloro-1,3-phenylenediamine, 6-chloro-1,3-phenylenediamine, 3-chloro-1,4-phenylenediamine or a mixture thereof, the acyl halide compound is trimesoyl chloride, isophthaloyl chloride, terephthaloyl chloride, or a mixture of two or more types thereof, and the additive is represented by the following Chemical Formula 1 or 2: in Chemical Formulae 1 and 2, m and n1 to n3 are an integer of 1 to 10; and X1 to X3 are each a hydroxyl group; or an alkyl group, and at least two of X1 to X3 are a hydroxyl group. an amine compound; a chain-type-structured additive containing one or more amino groups and two or more hydroxyl groups bonding to a carbon atom; and a surfactant, wherein a content of the amine compound is from 0.001 wt% to 10 wt% based on 100 wt% of the composition for interfacial polymerizing polyamide, a content of the additive is from 0.01 wt% to 1 wt% based on 100 wt% of the composition for interfacial polymerizing polyamide, a content of the surfactant is from 0.005 wt% to 0.5 wt% based on 100 wt% of the composition for interfacial polymerizing polyamide, the 'chain-type structure' means a structure that does not include a ring, the polyamide active layer has a number of hydroxyl groups, the amine compound is m-phenylenediamine (mPD), p-phenylenediamine, 1,3,6-benzenetriamine, 4-chloro-1,3-phenylenediamine, 6-chloro-1,3-phenylenediamine, 3-chloro-1,4-phenylenediamine or a mixture thereof, the acyl halide compound is trimesoyl chloride, isophthaloyl chloride, terephthaloyl chloride, or a mixture of two or more types thereof, and the additive is represented by the following Chemical Formula 1 or 2: in Chemical Formulae 1 and 2, m and n1 to n3 are an integer of 1 to 10; and X1 to X3 are each a hydroxyl group; or an alkyl group, and at least two of X1 to X3 are a hydroxyl group. m and n1 to n3 are an integer of 1 to 10; and X1 to X3 are each a hydroxyl group; or an alkyl group, and at least two of X1 to X3 are a hydroxyl group.