The Water-flowing fractured zone’s height and its distribution has an important effect on stability of the surrounding rock and the safety in the subsequent production under reservoir. In the paper the Drucker-Prager yielding law is used. The limit value of tensile stress and shear stress is used to judge the water-flowing fractured zone’s height and its distribution. The fitting formula is obtained by origin software under different advance of the work face. The peak value of horizontal movement is 1.13m. The symmetrical subsidence basin is formed in the center of work face. The peak value of subsidence is 3.86m. The sum of surface subsidence accounts for about 43 percent of the mining height. The advance of around 300m is the distance that the water flowing fractured zone’s height reaches the highest value. The biggest height of water- flowing fractured zone is 146m.