Abstract:Dagaozhuang iron deposit is a large middle sized sedimentary metamorphic iron deposit. Through hydrogeology survey, reformer information and hydrogeology survey of underground tunnels, hydrogeological characteristics and water filling source of this deposit have been found out. It is showed that its hydrogeological boundary condition is simple and hydrogeological condition is medium type. Combining with actual water inflow, by using the "long and narrow adit method " and " big well method ", normal water inflow and largest water inflow at different elevation have been predicated. It can provide reliable basis for deposit in deep mining.