Abstract: in order to solve a poortop cal caving and low coalrecovery problems in the ful mechanized top coal caving mining in the utra thck sean with partngs.a theoretical analys s,nunerical sinulation.sie measurement and oter study method were appied to estabish a boom beam model wth partings and broken nonunfom distrbuted oadings.The paper analyzed the paringlcation and paring thickness to the mechanics role mechanismo of the boom beam broken.The numericalsimulation was applied to compare and analze th different parting location and different parting thickness affected to the breaking mechanism and caving of the top coaand the partings.Based on the circunstances.the relevant tachnical soluton measures were provided and apalild to the mine site . The results showed that the max broken distance of the parting in No.8203 coal mining face of Jinzhuang Mine Datong Coal Mine Group wasup 6. 5 m an the midleparing and tick seam paring woubbe ighly affected to the top coal caving. The deep borehole pre-frcturing blasting and tvo interval cal blasting and other measures could be efectively improve the op coal caving and the top coal mining recovery rate.