Abstract: The mainly method of iron mine to recycle part of marginal ore-body are non-pillar sublevel caving，the auxiliary methods are shrinkage and room and pillar mining.The mine is improving mining and dressing ability and expanding production.The mining method which sublevels open stoping with subsequent backfilling will be carried on to the part of ore-body.The changing rules of internal structure about filling body and the relationship between proportioning parameter and uniaxial compressive strength can be obtained though the test of physical and chemical properties，analysis of sand level，SEM test，the test of ore-body with different proportioning test in 7days，28days and 60days.The effect of unclassified tailings characteristics to the quality of filling body can be effectively evaluated by the test results and analysis.The purpose of all of these is providing achieving theoretical foundation for efficient and safe production.