Based on the actual mining conditions of deep stope of 1021-2 fully mechanized coal mining face of Linxi mine, the height division of "Three Zones" was analyzed by using the method of combining of theoretical analysis , FLAC3D numerical simulation and field observation, with combing the practical situation of the mine, drawing conclusions that the height of caving zone and fracture zone reaching 10.3 ~ 12.1 m and 37.6 ~ 42.2 m, the study could provide theoretical guidance for studying the migration law of overburden strata of the working face, with certain guiding and referential significance for the division of the height of "Three Zones" of deep stope under similar geological conditions.