A slope will slide if the unbalanced force does not tend to zero when the stability of the slope is analyzed with the help of FLAC. Thus the ultimate reason of slope sliding is the unbalanced force determined by FLAC. The slope will remain stable if the unbalanced force is counterbalanced by a reinforcement force which is produced by a suitable reinforcement method. In this paper, the stability of the slope was analyzed by using FLAC, and the unbalanced force of the slope was obtained through the FISH function in FLAC. According to the equilibrium conditions, the rela- tionship between the reinforcement force and unbalanced force was derived and accordingly the reinforcement force was determined. The reinforcement design was adopted by using pre-stressed anchor bars on the basis of the reinforce- ment force. An example is used to show that the effect of slope reinforcement based on the reinforcement force is safe and economical. The method doesn’t need to suppose a sliding surface to obtain the reinforcement force, and it is also clear in physical meaning. So this method realized the organic unification of the stability analysis and the slope rein- forcement A slope will slide if the unbalanced force does not tend to zero when the stability of the slope is analyzed with the help of FLAC. Thus the ultimate reason of slope sliding is the unbalanced force determined by FLAC. The slope will remain stable if the unbalanced force is counterbalanced by a reinforcement force which is produced by a suitable reinforcement method. In this paper, the stability of the slope was analyzed by using FLAC, and the unbalanced force of the slope was obtained through the FISH function in FLAC. According to the equilibrium conditions, the rela- tionship between the reinforcement force and unbalanced force was derived and accordingly the reinforcement force was determined. The reinforcement design was adopted by using pre-stressed anchor bars on the basis of the reinforce ment force. An example is used to show that the effect of slope reinforcement based on the reinforcement force is safe and economical. The method does not need to suppose a sliding surface to obtain the reinforcement force, and it is also clear in physical meaning. So this method realized the organic unification of the stability analysis and the slope rein- forcement