The invention relates to the technical field of cold heading steel, and particularly discloses high-strength atmospheric corrosion-resistant cold heading steel and a preparation method thereof. The high-strength atmospheric corrosion-resistant cold heading steel comprises, by weight, 0.28%-0.40% of C, 0.15%-0.30% of Si, 0.60%-0.90% of Mn, smaller than or equal to 0.025% of P, smaller than or equalto 0.020% of S, 0.60%-1.00% of Cr, 0.20%-0.50% of Ni, 0.20%-0.45% of Cu, 0.005%-0.050% of Ti, any one or more elements of 0.15%-0.35% of Mo, 0.09%-0.12% of V and 0.005%-0.015% of Nb, the balance Fe and unavoidable impurities. The cold heading steel prepared through the method has the high strength and hardness, has the good hardenability, meets the requirements of the hardenability of large-sizebolts, has the certain delayed fracture resistance, is low in production cost and has the characteristics of being good in corrosion resistance, high in tensile strength, good in surface quality and excellent in performance.