Applying　similarity　simulation　test　in　engineering　background,　the　rock　strata　and　ground　surface　movement　over　strip　mining　and　the　grouting　backfill　in　caving　area　with　strip　mining　were　studied.　The　results　show　that　the　grouting　backfill　in　caving　area　with　strip　mining　can　reduce　caving　angle　and　caving　height　of　roof,　prevent　the　major　key　strata　in　overburden　from　breaking,　and　limit　the　radial　deformation　of　strip　coal　pillar,　making　the　adjacent　caving　space　unable　to　be　connected.　When　the　backfill　volume　is　30%,　the　extraction　volume　can　increase　by　25%;　in　this　case,　it　can　decrease　ground　deformation.