Abstract: In order to ensure the implementation of grouting filling and subsidence reduction in overburden strata of island working face, and liberate the coal under buildings, the aspects of drilling fluid leakage, electric logging, TV imaging, coupling relationship between grouting amount and grouting pressure was analyzed to provide a basis for the grout ability of overburden strata separation. Through the filling plane formed by grouting near the goaf in No.12030 island working face. it showed that the strip support zone could be formed in the goaf under the action of high-pressure grouting filling, which provided a preliminary basis for the implementation of overburden separation grouting filling non-relocation mining in the island working face.