Abstract: In order to have the early warning index and early warning criterion of the powered support jammed accident monitoring and measuring in the fully-mechani zed coal mining face,based on the domestic monitoring and measuring status,with the analysis on the accident cases ,the study on the mine strata pressure theory and the analysis on the site measured data,the paper studied the factors to cause the roof disaster of the fully-mechanized coal mining face and provided six early warning indexes of the roof disaster occurred in the coal mining face ,including the initial setting pressure passed rate. safety valve opening rate,no pressure keeping rate,unbalanced rate,ro of weighting step distance and roof stress as well as the geological abnormal region. A real-time and automatic analysis algorithm of the early warning index was obtained f rom the study and a monitoring and early waning platform of the roof disaster was established for the fully-mechanized coal mining face. The platform was successfully app lied to the Yousanpian fully-mechanized coal mining face in Tiebei Mine, Zhalainuoer Coal Industry Company Limited China Huaneng Group. With 24 h continuous monitorin g and early warning and the on time effective measures conducted,the performances of the powered supports were improved obviously. The advancing rate of the coal mini ng face was speeded up and the annual coal production of the coal miming face was increased from less 2. 50 million t to 3. 50 million t. The platform was successfully app lied to a high cutting and high inclined coal mining face in Huashan Mine of Sichuan Panzhihua Coal Industry Group Company Limited. The initial setting load level was obv iously improved and the falling down and sliding prevention problems of the powered support was effectively solved. Meanwhile,the successful application of the platform t 0 Wanbei Coal and Electric Power Group Corporation Limited obviously improved the roof control level and avoided several roof accidents occurred.