Abstract: According to a poor stability and high difficult control problem of the powered support-surrounding rock system applied to the fully-mechanized top coal caving mining face in the high inclined soft seam, a site observation, theoretical analysis and mechanics modeling combined method was applied to study the unstability process of the roof, coal wall, powered support and floor during the mining process. The results showed that the stability of the top coal, coal wall, powered support and floor system in the fully-mechanized top coal caving mining face in the high inclined soft seam was poor and there was unstability mechanism of the mutual disturbance and malignant mutual collapse existed between each factor. The paper pointed out that the key to control the stability of the coal mining face was to control the top coal leakage and falling and the coal wall spalling and could provide the references to control the stability of the powered support-surrounding rock system in the fully-mechanized top coal caving miming face in the high inclined soft seam.