Abstract: The narrow coal pillar width of roadway driving along next goaf in fully mechanized top face is reasonable or not directly related to the deformation of roadway and support costs. Aiming at the problem of narrow coal pillar width identified with large section roadway driving along next goaf in fully mechanized top caving face, the influence laws of mining to different width of narrow coal pillar deformation and stress distribution was studied by using numerical simulation of FLAC3D, the reasonable narrow coal pillar width was determined and successfully applied to engineering practice. Some conclusions can be drawn as follows:(1) With the increase of the coal pillar width, without damage area is also increasing; (2) With the working face advance, the vertical stress distribution by the trapezoidal distribution has gradually evolved into a triangular distribution, ahead of 20m is a turning point, to return along the trough strengthening support; (3) The coal pillar width has great influence on distribution of stress influence, with decreasing the width of coal pillar, the vertical stress distribution by the trapezoidal distribution has gradually evolved into a triangular distribution; (4) The displacement of the coal pillar to the roadway was increased gradually with pillar width, and advanced the working face 5m and coal pillar reaches 6 m, tends to be stable; (5) The 5m coal pillar was chosen as the pillar's stress condition better, and grouting reinforcement can satisfy the need of engineering. The research results can provide reference to the design，construction and study for similar projects.

Key words: large section, roadway driving along next goaf in fully mechanized top face, narrow coal pillar width, numerical simulation, failure mechanisms