Abstract: In order to control the ground subsidence, protect the agricultural fields and safely caving under the building, in-situ test of the strata(bed) separation grouting by fully mechanized top coal caving have been improved several times in the Yanzhou Coal Area. During the test, the dynamic principles of development of strata(bed) separation have been studied. Its conclusion is suited to apply the technology of the strata(bed) separation grouting under the similar condition.