The invention relates to an anti-corrosion coating, in particular to an epoxy glass flake heavy-duty coating and a preparation method thereof. The epoxy glass flake heavy-duty coating is prepared by mixing and curing a component A and a component B. The epoxy glass flake heavy-duty coating can be coated on the surface of a steel structure, and can be taken as a primer together with an epoxy zinc-rich primer. When taken as a finish coat, the anti-corrosion coating has high antirust and anti-corrosion performance. As proved by detection, a paint film does not become foamed or rusty when the salt spray resistance reaches 5,000 hours and has high weather resistance, and the coating and maintaining costs of a steel structure can be lowered. The production method of the epoxy glass flake heavy-duty coating does not need post-treatment, so that the process method is simple, energy is saved, and the cost is low. The component A and the component B can be automatically dried into a film at normal temperature after being uniformly mixed, so that high film forming performance is realized, and the product has high storing stability.