Abstract: in a mining procss ofNo.42103 ful -mechanized top coal caving miming face in BueralMine,the powered suppors would frequently cause the bench subsidence and even jamming henomenon.Based on the analysis on the rational worcing res stance of the powered suppors in No.42103 ruly-mechanized top coal caving mining face a stuty nethod combined with a theoretcal derivation and a site meaurement was aplied to the calculation on the roof movement aw ofthecoal mindng face. A roo structure model of No.42103 rulymechanized top coal caving mining face was establis hed.The interelaton between the powered support and surounding rock was analyzed.T he roof stuctre model method and the dynamic load coeicient method were applied to comprehensivly calculate and detemine the rationaworking resistance of the powered suppor in Nc.42103 ruly-mechanized top coal caing mining fac.The studl resuls showed tht the of pressure of o.42103 ull.mechanized top coal caving mining face was 1.53 MPa.the rational working resistanceof the powered supportwa 18 709 kNand the ratihnalsupport itensty was 1.71 MPa.