<p>This study proposes a phase-field adaptive interpolation material point method (PF-AIMPM) to simulate ductile crack propagation and large deformation failure in pressure-sensitive geomaterials. Based on the microforce balance law and the second law of thermodynamics, a nonlocal phase-field fracture model is formulated as the damage evolution mechanism within an elastoplastic framework. By decomposing the stress tensor, the total free energy is separated into crack-driving and non-driving components, and an effective phase-field stress is introduced to construct a stress update scheme suitable for elastoplastic constitutive modeling. To address large deformation issues during dynamic ductile fracture, an adaptive interpolation technique is employed, and an explicit formulation of the lumped phase-field stiffness matrix is developed to suppress numerical noise caused by material points crossing cell boundaries and to enhance computational accuracy in brittle-ductile transition simulations. The accuracy and robustness of the proposed method are validated through two benchmark examples: a single-edge notched tension test and a ductile fracture test of geomaterials. A centrifuge model test of an excavated compacted clay slope is numerically simulated, demonstrating that PF-AIMPM can accurately capture crack initiation and propagation, as well as the progressive failure process and slip-induced dilation behavior.</p>