Fire retardant coating for steel structure surface of nuclear power plant

The invention relates to a fire retardant coating for a steel structure surface of a nuclear power plant. The fire retardant coating consists of components A, B and C at a weight ratio of (4-6): 1: 1, wherein the component A is a mixture composed of 15-35 parts of epoxy resin, 2-10 parts of reactive diluent, 5-15 parts of dehydration catalyst, 10-30 parts of carbonizing agent, 5-20 parts of foaming agent, 15-35 parts of fire retardant, 5-15 parts of smoke inhibitor, 10-30 parts of pigment and filler and 2-10 parts of auxiliaries; the component B is a mixture composed of 10-50 parts of toughened resin, 10-30 parts of pigment and filler and 2-10 parts of auxiliaries; the C component is an amine curing agent; and the toughened resin in the component B is hyper-branched polyester resin with a terminal carboxyl group. The fire retardant coating disclosed by the invention is more excellent than a normal intumescence fire retardant coating in binding strength, freezing and thawing cycle resistance, acid and base resistance, and fire retardant limit, and is specifically up to fire resistance requirements of the steel structure surface of the nuclear power plant.