To improve the mechanical properties of anti-corrosion coating substrate, a combined amine curing agent suitable for anti-corrosion substrate is developed; meanwhile, to reduce the water absorption of the substrate to meet the requirements of heavy-duty, the modification method of epoxy resin by polysulfide rubber is improved. The mechanical properties of different curing products were tested to select the best combination amine curing agent; Dynamic mechanical analysis (DMA) and gel permeation chromatography (GPC) were applied to the matrix prepared by conventional modification method and improved modified method respectively. The surface morphology and section morphology were observed by means of metallographic microscope and scanning electron microscope (SEM). At the same time, electrochemical impedance spectroscopy (EIS) technology was used to explore the influence of the improved modification method and conventional modification method on the anti-corrosion performance of polysulfide modified epoxy coating. The results showed that the tensile strength of the curing product with D230 and AEP could reach 19.47 MPa, and the shear and tensile bond strengths could reach 18.02 MPa and 22.09 MPa respectively. The bonding strength with steel increases with the increase of D230 content, when the mass fraction of D230 in the curing agent was 84%, the adhesive strength was the highest. The saturated water absorption of the substrate prepared by the improved modification method was only 1.7%. The |Z|0.1 Hz value of the coating with a thickness of 50μm was still close to 108 Ω/cm2 after soaking in 3.5% NaCl solution for 7 days, which showed that the coating has excellent corrosion resistance. The mechanical properties of the curing products with curing agent D230 and AEP are the best, and the curing agents of D230 and AEP have little influence on the microstructure of the curing products, and the mechanical properties such as tensile strength of the cured products are less affected by the content of curing agent; Compared with the conventional method, the water resistance, mechanical properties and corrosion resistance of the matrix prepared by the improved modified method are greatly improved. The final polymer matrix is suitable for heavy-duty protection because of its low water absorption, good mechanical properties and excellent corrosion resistance.