Abstract: iin order to detemine the height of overburden falure of the steep thick seam horizontal siting full - mechanized caving mining taking Meie Mine as the experimental mine,the paper adopted borehole fushing fuid oss oservation metod to measure the overburden falre height in combination with the overburdenfaure evoluton characteristics and development height simulaton resulis with UDEC sofiware,the expeced fomuia of waterconducted zone heght of horzontalscin aul mechanized caving mining was obtained.The results showed tat the overburde fralre height inreased with the layers the maximum height of overburden was sg nificantiy inhibried,the carck height and the cumulative ratio of mining depth and minin thickness was significantly decreased;,the terminal development form of over)urden was obvious ach type and located on theroo s d e; overburden caving angle increased with the increase of mining ticing numiber.Based on the above analysis esults,the overburden failure height of steep thick seam horizontal slicing fully- mechanized caving mining in Meine Mine was obtained.