Abstract: This study aims to address the insufficient deformation response and the difficulty in optimizing structural parameters in the design of magnetically actuated flexible actuators for complex bending–twisting motions. A layered NdFeB/silicone magneto-responsive actuator with pea-pod-like bending–twisting behavior was fabricated using direct-ink-writing (DIW) 3D printing, and the magnetization directions of the embedded magnetic particles were reoriented under a guiding magnetic field to construct programmable structures with controllable orientation of magnetic particle chains. A Box–Behnken design in response surface methodology was adopted to perform multi-factor and multi-level analyses of key variables, including magnetic field strength, magnetic particle mass fraction, and geometric parameters, and predictive models of bending and twisting responses were established. The results show that the models are highly significant (p < 0.0001) with insignificant lack-of-fit (p > 0.05), indicating that they accurately describe the coupled influence of structural and material parameters on bending–twisting performance. Under the optimized conditions, the maximum torsion angle increases from 6.7° to 9.4°, representing a 40% improvement, and the bending–twisting synergy is significantly enhanced, demonstrating a strong cooperative effect between magnetic-domain orientation and structural design. This work reveals the key role of internal particle magnetization in bending–twisting actuation and provides an optimization strategy based on the coordinated tuning of magnetic orientation and structural parameters, offering a practical route for the design and formulation of high-performance magnetically actuated bending–twisting actuators.