Abstract: Based on the high precision microseismic monitoring technology and the rock mechanics and rock pressure theory, overburden strata movement law has been gained at 3107 working face in Shengjian Coal Mine，and the relationship between support and surrounding rock on the fully mechanized top coal caving face in thick coal seam of kilometer deep mine has been studied．The results show that the microseismic events located within the lower strata are of high density distribution，and microseismic events located within the higher strata are of low density distribution．The periodic distribution of microseismic events in both space and time correspond to the periodic movement of roof strata，and the high rock fracture force the lower strata fracture．The relationship between support and strata high rock fracture force the lower strata fracture．The relationship between support and strata with pe- riodic rock fracture of the basic roof can be drawn as follows：1) In the aperiodic weighting period，the basic load of the support originates in the static pressure caused by such forces as the top coal of 4.4 meters thickness，the lower immediate roof of 20 meters thickness and part of the upper immediate roof of 20 meters thickness；2) In the periodic weighting period，the basic load of the support originates in the dynamic pressure caused by the basic roof fracture and the static pressure caused by the weight of the top coal and the immediate roof．The dynamic pressure causes impact load on the support，which is the main reason that hydraulic support is crushed．Some measures such as decrease of top coal recovery rate in advance and increase of support extension should be taken so as to reduce the impact on the hydraulic support．

Key words: thick coal seam, kilometer deep mine, fully mechanized caving face, microseismic monitoring and measuring, relationship between support and surrounding rock