The invention relates to the technical field of building materials, in particular to an energy-saving environment-friendly light security fire door core plate applied to a steel structure, a wooden structure and a steel wooden structure. The energy-saving environment-friendly light security fire door core plate comprises magnesium chloride, fly ash and water, which is characterized by further comprising magnesium oxide, waterproof glue, industrial-grade hydrochloric acid and magnesite plate material vesicant, wherein the energy-saving environment-friendly light security fire door core plate comprises the following components according to parts by weight: 15 to 25 parts of magnesium chloride, 10 to 15 parts of fly ash, 20 to 30 parts of water, 35 to 45 parts of magnesium oxide, 0.5 to 1.5 parts of waterproof glue, 0.5 to 1.5 parts of industrial-grade hydrochloric acid and 0.5 to 1.5 parts of magnesite plate material vesicant. The energy-saving environment-friendly light security fire door core plate has the advantages of energy saving, environment protection, no toxicity and harm to a human body, favorable properties of fire prevention, water prevention, insulation and heat insulation, good sound-absorbing effect, high strength, long service life, and the like; and the manufacturing method of the energy-saving environment-friendly light security fire door core plate has the advantages of simple technology, short procedure, minimum cost, and the like.