Pre-stressed anchor cables are widely used in slope engineering for effectively improving slope stability as a reinforcement measure. Based on assumptions of stresses on a slip surface, this work proposes a new limit equilibrium (LE) method to analyse the stability of slopes reinforced with anchor cables. Meanwhile, the nonlinear Mohr–Coulomb (M–C) strength criterion has been adopted to describe the slope sliding for shear failure of the slip surface. Then, after comparison and analysis of several examples, the feasibility of the proposed method is verified. Compared with the traditional LE methods, the proposed method has a simple calculation process without iterative loop calculation of the slope factor of safety, and a reasonable solution can also be obtained. Furthermore, the slope reinforced by anchor cables with more than a row can be simplified into a slope with a row to analyse its stability because the same stability would be obtained for the reinforced slope with different reinforcement patterns under an equivalent reinforcement relation. Thereafter, to facilitate the engineering application and optimize the design of anchor cable parameters, the stability charts of the reinforced slope under the linear M–C strength criterion are drawn.