In order to study the the feasibility of stoping-and-filling method and the optimal parameters of mining design in the southern district of Sijiaying iron mine,a model for the mining optimization of the southern district was established by seepage-stress coupling numerical orthogonal test.The effect of underground mining on ground rock movement and seepage field was revealed.The results showed that stoping-and-filling will not cause surface collapse,groundwater will gush into Goaf from surrounding rock in the course of mining,especially in stopes of the first and second level gushing water could introduce dangerous which should be preventing in advance.