The invention relates to an environment-friendly epoxy intumescent fire-retardant coating and a preparing method thereof, and belongs to the field of functional coatings. The environment-friendly epoxy intumescent fire-retardant coating is prepared from a component A and a component B, wherein the component A uses epoxy resin as a main film forming matter and is added with a reactive diluent, a catalyst, a carbon-forming agent, a foaming agent, fire retardant, auxiliaries and solvent, and the component B is composed of a curing agent, a curing accelerator, pigment filler, auxiliaries, refractory fibers and solvent. In the component A, the ratio of the epoxy resin to the reactive diluent is 1:1-5:1. In the component B, the ratio of the curing agent to the curing accelerator is 1:1-5:1, and the usage quantity of the refractory fibers accounts for 5-50% of the total mass. The environment-friendly epoxy intumescent fire-retardant coating is free of alkylphenol, or halogen compounds, or boron compounds or sulfocompounds. The prepared environment-friendly epoxy intumescent fire-retardant coating is good in acid resistance, alkali resistance, water resistance, ageing resistance and salt mist resistance and is particularly suitable for fire-retardant protection for maritime and severe outdoor environments, the petrochemical industry and places with hydrocarbon fire potential hazards.