Abstract: After transtering to deep open-pit mining, a series of problems would be caused such as the strip-ping trtio is higer, the preparation periods of new levels are longer and the transport system for minedevelopment is complex. Combined with practices of Waitoushan lron Ore Mine (the main miningarea) which had been transfered to deep open-pit operation and its capacity was decreased, this paperanalyses the concrete causes and suggestes the measures for their solving.