Abstract: in order to prevention of a roo falling accident occured at the conveyortall in No.52303 ruly-mechanized high cutting coal mining face,a theoretcal analysis site measurement and other mefhods were applied to analyze the main causes of the roo falling in No.5203cal mining face The main causes were an abnormal mine strata behavior.second mining infuence. slow pushing forward speed ste managing personme with instfrisint experiences and bean end d istance too ong of he transtion powered support. Based on the circunstances Marthan materal was applied to reinforce the cal all and roofRfocil mateial was appied to backil hehigh roo fallig area in the coal mining face and the technical measues were appied to enhance thegateway support near theconection gateway. The ste applicaton resuts showed tat the technical measures tinmely to change the lose structure of the surounding ock could fectively resit the ceal all spaing and the rof illng and could improve the integrated strength of the coal nd rock. During the pushing forward pro.ess ofthecoal mining fac ,there were no obwious roo raing and spalling accident occurred and the waste rock leakage from the roof of the coal mining face was effectively controlled.