Abstract: On the background of Zhangjiawa iron mine's slow incline and thin ore body condition of Luzhong metallurgy mining group company,the paper has researched the relation between constructional parameter and recovery index of along vein collocating drift's non-pillar sublevel caving through adopting simulating experimental method in laboratory and has optimized constructional parameter.On the base of economy comparison,the paper has made certain the commend value of sublevel height in order to provide theory basis for Zhangjiawa iron mine deeply mining.