In nature or human engineering activities, the crack generation of soil slope is not only related to the properties of rock and soil, but also to the geometry of the slope. In order to study the stability of irregularly shaped cracked soil slopes, based on the upper bound theorem of limit analysis and the strength reduction method, an energy balance equation for n-level irregularly shaped cracked soil slopes was constructed, and the expression of the safety factor was derived. The influence of the slope shape concavity and convexity, crack position, and crack depth on the stability of the slope was explored. The results show that when the equivalent straight slope angle β₀ is 30° and the concave point is near the foot of the slope, the concave slope is less stable than the straight slope. When the convex point is near the slope foot, the convex slope is more stable than the straight slope. In the convex shape, the critical crack depth δ/H_min first decreases and then increases, and the critical position δ/H_min gradually approaches the slope when the convex point moves upward. In the concave form, x/H_min increases first and then decreases, and x/H_min gradually moves away from the slope during the upward movement of the concave point. Finally, combining the method with the actual project, it is concluded that the effect of the tensile crack on the slope stability is weakened with the increase of the slope body concave-convex degree and slope height. The research results can provide some theoretical basis for similar slope engineering.