The invention relates to a resin composition and a method for preparing an FPC coverlay by using the same. The resin composition comprises the following components in part by weight: 50 to 70 parts of flexible saturated polyester, 30 to 50 parts of hard saturated polyester, 1 to 20 parts of enclosed isocyanate curing agent, 15 to 150 parts of pigment, 15 to 120 parts of inorganic filler, 0.5 to 2.5 parts of antifoaming agent, and 5 to 30 parts of organic solvent. The resin composition is applied to the FPC coverlay in a flexible printed circuit. The resin composition has the characteristics of excellent weather resistance, high covering power, high flexibility and adhesiveness, and the like. The method for preparing the FPC coverlay by using the same can realize the one-off coating of the FPC coverlay on the flexible printed circuit, has the advantages of simple manufacturing method, low cost and high yield, and can realize the continuous production and obviously improve the production efficiency. The FPC coverlay produced by the method can improve the contrast ratio of an LED rope light under the action of an insulating base film besides excellent dust prevention, corrosion resistance, weather resistance and other characteristics.