Abstract: Aiming at higher capacity problem of Nansigou waste dump in Antaibao open-pit coal mine，Combined with the actual situation，the main factors which influence the stability and the landslide model of this dump were analyzed，drainage rock parameters optimization method and work procedures were introduced.At last.Through the optimization analysis,the minimum working flat width narrowed from 65 m to 60 m, the overall slope Angle increased by 17 ° to 19 °,and the displacement capacity increased by 50 million m3.the practical significance of this method in ensuring the safety of production、increasing the dump capacity and alleviating the dump pressure,etc. were instructed.