Loess exhibits substantial anisotropy, and the shear strain induced by this anisotropy under cyclic spherical stress—common in dynamic stress fields—cannot be neglected. This study investigates the development of shear strain development in loess under different conditions through cyclic spherical stress tests, revealing the formation mechanism under cyclic spherical stress from the perspective of anisotropy. Results show that anisotropy-induced shear strain under cyclic spherical stress paths is substantial and can be separated into reversible shear strain and irreversible shear strain components. Irreversible strain comprises a negative component caused by initial anisotropy and a positive offset component resulting from stress-induced anisotropy. As the consolidation spherical stress and moisture content increase, the samples tend to be isotropic, thereby reducing both reversible and irreversible shear strain. Conversely, higher cyclic spherical stress amplitude accelerates shear strain development. Reversible shear strain amplitude is minimally affected by cycle number and consolidation stress ratio, decreasing with elevated consolidation spherical stress but increasing with higher moisture content and cyclic stress amplitude. Finally, a predictive model for irreversible shear strain under cyclic spherical stress is established based on the memoryless property of geometric distribution.