The invention discloses a polyaspartic acid ester resin, a preparation method, and an anticorrosive paint and preparation method thereof. The resin is mainly prepared from following raw materials in parts by weight: 2 to 5 parts of amino silane modified graphene oxide, 10 to 30 parts of binary primary amine, 0.1 to 0.3 part of alkaline catalyst, and 25 to 25 parts of maleate. The preparation method comprises the following steps: stirring amino silane modified graphene oxide, binary primary amine, and an alkaline catalyst, heating, dropwise adding maleate, heating, carrying out reactions at a constant temperature, and cooling. The anticorrosive paint is prepared by blending a component A and a component B, wherein the component A comprises aliphatic isocyanate and an elastic curing agent, and the component B comprises polyaspartic acid ester resin, an anti-settling agent, a pigment, a filling material, a molecular sieve, an antifoaming agent, a leveling agent, a dispersant, a hydroxyl acrylic resin, and an organic solvent. The invention also discloses a preparation method of the anticorrosive paint, which has the advantages of high solid content, good coating elasticity, good impactresistant performance, and excellent anticorrosive performance. The resin dispersibility is good.