Provided are a plated steel sheet and a method for manufacturing same, the plated steel sheet comprising: a base steel sheet; a Zn—Mg—Al plating layer provided on at least one surface of the base steel sheet; and an Fe—Al inhibition layer provided between the base steel sheet and the Zn—Mg—Al plating layer. The plating layer comprises, by weight %, 4 to 10% of Mg and 5.1-25% of Al and the remainder being Zn and unavoidable impurities with respect to components not including iron (Fe) diffused from the base steel sheet. The plating layer comprises a 24-50% MgZn2 phase in phase fraction. In the MgZn2 phase, an Al single phase is present in the ratio of 1-30% relative to the cross-sectional area of the total MgZn2 phase.