Abstract: In geotechnical engineering, natural sedimentation processes typically induce soils with inherent anisotropy in soils to a certain extent; so that mechanical properties such as strength, stiffness, and deformability show obvious directional dependence. Under external loading, the internal structure of soil evolves during continued loading, and produces to stress-induced anisotropy, which in turn affects the mechanical behavior of the soil. Furthermore, extensive experimental evidence indicates that soils generally exhibit non-associated plastic flow and significant state dependence during shearing. To concisely and rationally describe these characteristics, this study proposes a fractional anisotropic constitutive model applicable to soft soils, based on a modified Cam-clay yield criterion. The model can achieve state-dependent non-associated plastic flow without requiring an additional plastic potential function or state parameters, and capture soil behaviors, such as stress-dilatancy, more accurately. Finally, the model's validity is verified by simulating soft soil under various stress paths, including conventional triaxial compression and hollow cylinder torsional shear tests. The results demonstrate that the model predictions are in good agreement with experimental data, confirming its effectiveness in representing the complex mechanical characteristics of soft soils.