The invention discloses a high-strength anti-cracking thermal construction concrete material and a preparing method thereof. The material is prepared from, by weight, 85-100 parts of cement, 20-30 parts of magnesium oxide, 10-25 parts of graphite tailings, 15-35 parts of nanometer porous silicon particles, 10-15 parts of expansion clinker, 18-25 parts of recycled building aggregate, 10-20 parts ofcoal ash, 20-25 parts of hydroxypropyl methyl cellulose, 10-15 parts of silica fume, 10-20 parts of polycarboxylic acid efficient water reducer, 5-10 parts of redispersible powder, 8-15 parts of additive and a proper volume of water. By effectively matching cement, magnesium oxide, graphite tailings, nanometer porous silicon particles, expansion clinker, recycled building aggregate, coal ash, hydroxypropyl methyl cellulose, silica fume and polycarboxylic acid efficient water reducer, the reinforced concrete which has high compressive strength and breaking strength, can be well combined with existing concrete and is not prone to disengagement, excellent in overall performance and quite suitable for concrete work damage positions is obtained; the production process is simple.