Abstract: Take example for 15 coal seam of Chang’gouyu mine, RFPA^2D software is used to simulate roof failure process of steep-inclined coal seam with working face moving forwards. Research results indicate that roof supporting pressure of workface is decreased as the roof failure range increased. There exists first weighting and periodic weighting during roof failure process, but strata behavior is not obvious during periodic weighting. Synchronously with the increase of mining depth, floor begins to failure with low depth. Research results have Significance to safe productivity of mine.