Abstract：By dynamic simulation model tests，the distribution law of dynamic load of key roof stratum and the law of transmission of dynamic load on key roof blocks，key block A，B and C，are revealed. There are 4 load areas on the key roof stratum，and the mining face is just under the load reducing area of key block B. During the roof structure movement，the load of key block B will reduce by about 50% in about 30 minutes. These results are considerable significance to the understanding of the soil damage mechanism under mining and to the establishment of the theory of dynamic roof structure.
