The invention relates to an anti-corrosive alloy coating for a power transmission tower and a fastener and a preparation process of the anti-corrosive alloy coating. The anti-corrosive alloy coating is prepared by pickling, aided plating, drying, hot dipping, air cooling and other technological processes. The coating comprises the following components: 0.01 to 2.5% of Al, 0.01 to 0.5% of Mg, 0.06 to 2% of Re, 0.02 to 1.5% of Cu, 0.05 to 0.3% of Cr, 0.005 to 0.01% of Nb, 0.005 to 0.01% of Ni, 0.002 to 0.06% of B, and the balance of Zn. The alloy coating is used for prolonging the anticorrosive lifetimes of steel for the power transmission tower and the fastener under a complex salt-spray environment, and prolonging the anticorrosive lifetimes more than 10 times that of an industrial hot galvanizing pure-zinc product on the premise that the thickness of the coating is not increased.