A non-linear elastic incremental analysis method for reinforcement loads is introduced in view of the fact that most available methods are not suitable for reinforced soil slopes under working stress conditions. The method is based on the generalized Hooke’s law in the light of the soil-reinforcement compatible deformation at the potential failure surface and the nonlinear elastic constitutive relation of soil with Duncan-Chang model. The analytical results of three slope examples with different inclination angles by incremental analysis method are compared with those by finite element method. The comparison results reveal a very high accordance between the two methods for vertical slopes, which indicates that the incremental analysis method is very suitable for reinforced vertical slopes; but when the angle between slope surface and vertical direction increases, the difference of the results increases, which could be modified by reduction factor. Incremental analysis method has a broad application range with advantages of being simple, practical and efficient. This research is expected to promote understandings of the mechanism of the interaction between soil and reinforcement, and shed some light on the design of geosynthetic-reinforced slopes.