Despite the wide spread of surface composite reinforcement of masonry structures, there is not enough information concerning methods of calculating such reinforced structures in the actual normative literature. The article proposes a numerical model for estimating the effect of composite reinforcement on the bearing capacity of a compressed-bent masonry wall which is constructed on the basis of experimental studies of walls from cellular concrete blocks. The numerical model takes into account the plastic work of the masonry under compression and the possibility of crack formation. Theoretical curves are obtained for the dependence of the bearing capacity of reinforced and nonreinforced masonry on the relationship between the compressive force and the bending moment. It is shown that the accepted reinforcement gives the greatest effect in the range of loads from pure bending to compression with bending at a compressive load value equal to half the failure load under pure compression. Such numerical design model can be used to evaluate the effect of reinforcing vaults and walls loaded eccentrically, or from the plane, and other similar structures.