The invention relates to high-strength easy-molding atmospheric corrosion resistance steel for a transmission tower and a preparation method thereof. The steel mainly comprises the following chemical components in percentage by weight: 0.02 to 0.058 percent of C, 0.018 to 0.10 percent of Si, 0.60 to 1.30 percent of Mn, less than or equal to 0.025 percent of P, less than or equal to 0.010 percent of S, 0.15 to 0.40 percent of Cu, 0.036 to 0.30 percent of Ni, 0.045 to 0.12 percent of Al, 0.005 to 0.06 percent of Ti, 0.0010 to 0.0030 percent of Ca, and the balance of Fe and unavoidable impurities. The high-strength easy-molding atmospheric corrosion resistance steel for the transmission tower has the advantages of high strength, good welding performance, cold roll forming performance, low-temperature impact toughness, and good atmospheric corrosion resistance.