Abstract: In view of the problem of shallow buried depth face mine pressure rule is complex and with numerous influencing factors, through the theoretical analysis and field monitoring and numerical simulation method to study on the shallow buried depth face mine pressure characteristics of the working face length effect. Conclusion is obtained that: Working face length increase has remarkable effected on the mine pressure characteristics, working face length direction exist with the working face length evolution "composite pressure arch" structural over length fully-mechanized sublevel caving mining working face to pressure step distance decrease, mine pressure distribution in working face is central to axis of symmetry of the arch distribution. With the working face length increases, the working face front abutment pressure influence scope, peak position and size are different. When the working face length is 130 m, the abutment pressure peak is located in front of the working face 13 m, its peak value is 6.7 MPa (propulsion 50 m).When the working face length increased to 230 m, the abutment pressure peak position is located in front of the coal wall 8 m, its peak size is 8.5 MPa (propulsion 50 m), bearing stress peak size corresponding increases, but the peak position transfer coal wall direction close to working face, but with the working face length continue to increase, the abutment pressure peak position will no longer change.