Abstract: In order to study the rule of mining thick impact on dynamic subsidence characteristics under the geological and mining conditions in thick unconsolidated layers,on the basis of the surace movement otsevaion dala of Zhaogu CoalMime Are ,the infuen:e of mng thickrssimpact on characteris cs of sura:e ubisdence,the maxinmm ground snking speedthe maximumground sutisdence velocity lag n thefnlence of duaton ofground surace at ofere tsta es was analzred resetivly in co dtin of igunertikunco soidated lyers t as concbuded thatunder the conitin of thik ose bedwith increase of min ng tickrss.sura c sutosdencecoe Fivent inveases from 0.67 t0. 74.invesing neail "1k lfaxinmum sutisidene veloiy oi utace intreases rom 24.5md o 51 .1m d ncezse ty 109%; Thelag distance of maximum sutsdence veocit reduced from 182 m to 94 m by amost 4 %; Tnesurace movemen of ctive exended from 2068days to 252 days exended neary 23% thile the recssio durato reioed from 112 days io 62 days shoren eard 5%. Th resuls show tht tnder the condtie ofthtk unconsoited layes with the nrease of mning thickress the surtave suosden co rint ncesesthe nking seed beomes at ativeduraton xends ress on duratoenshrtens urace residual deformation becomes small and stability speeds fast and other characteristics.