Problem is brought forward by the weak soil layer and the soil near slide surface. The weight back analyzed is presented to solve the problem. For obtaining the weight coefficient, the division of the inclination curve is done. After that, the soil can be divided into several blocks. The displacement of the curve is described by two values: the sliding and the deformation displacement. The method of the weight coefficient calculation is proposed applying the deformation displacement. At last, the sensitivity of the new methods is calculated.