Abstract: According to the problems of complex structure overlying strata in the coal seam isolated coal face which is easy to cause rock burst during mining，a method of designing the width of the face before isolated face working was presented.Taking a mine in Shandong as the engineering background，firstly，according to the working conditions of the isolated island working face and the law of overlying strata movement to judge whether key layer breaking，the isolated working face of "Γ" type spatial structure of overlying strata was obtained；Secondly，the stress transfer law of the working face was analyzed by using the theory of mine pressure to estimate the static bearing pressure of isolated working surface；Finally，the overall support strength of the working surface was analyzed according to the stress distribution characteristics of the isolated working face.Combined with the instability mechanism of mining impact in working face，the proper range of the working face width was determined.By engineering analogy and theoretical calculation，the conclusion is that the width of the 3上 1105 isolated face working face was more than170 m，which provides a theoretical basis for the design of the working face width.

Key words: Mining engineering, Spatial structure of overlying strata, Isolated coal face, Bearing stress, Rock burst, Width design