This paper summarizes the geological features of Gangmiaoliu iron deposit, and analyses the ore-controlling structure. The deposit is a sedimentary metamorphic iron ore deposit. The ore-bearing rock series is located between the upper and lower magmatite member of Neo-Archean Tieshanmiao Formation. Spatially, the deposit is strictly controlled by the graben and horst fault blocks. The ancient erosion surface, the unconformity caused only complete oxidation of ore in the central ore block and has no major impact on the eastern and western blocks.