Abstract: To determine the reasonable working resistance of support during fully mechanized mining wi-th large mining height in Xiaobaodang coal mine, According to the certain- conditions of No. 2-2 seam, By similar simulation and numerical simulation and dynamicload method study the strata observation lawand support working resistance. The results show that the first weighting step distance is 68m,and the a-verage periodic weighting step distance is 16m. the dynamic load coefficient is 1.31, The dynamic load coefficient increases with the working surface and the intensity of mine pressure is medium. Comprehen-sive analysis If the 1.75×4.75m support was selected, the working resistance was determined to be 14000kN. Because of the high mining height and the basic roof is hard. The lower basic roof appeared in the process of cantilever beam structure, when the cantilever beam breaks, all its weight is borne by the s-upport, the support loading is large. The results provide reference for the determination of working resis-tance of similar conditions.