Abstract: Development of highly water flowing fractured zone of mining face to the rational design parameters to ensure safety mining has significant influence, which faults are an important factor affecting the development of highly conductive water flowing fractured zone. Effects of faults with different dips and drops on the height of water-flowing fracture zone in steep mining face with soft overlying strata have not been extensively studied now. Numerical simulation method was used in this paper to study these effects on the background of No.3 coal seam in Xinhe coal mine, and effects of dip and drop of fault on the height of water-flowing fracture zone in steep mining face with soft overlying strata were revealed. The results indicate that the height of water-flowing fracture zone increases with both dip and drop of fault, and the rate of increase is larger when the dip is larger than 60°and the drop is larger than 15m. The height of water-flowing fracture zone in steep mining face with soft overlying strata is more than 16 times than mining height, and it is higher when there are faults in overlying strata.it can reach more than 20 times.