<p>Exploring dielectrics with high gate capacitance and artificial tailoring of electronic states is highly desirable for the development of 2D electronics. Here, we report the synthesis of a single-crystalline ionic dielectric Sb₄O₅Cl₂ with aligned ionic channels, achieving a dielectric constant of 23.3 (at a thickness of ~ 25 nm) and non-volatile programmable regulation of the ionic migration. The fabricated 2D MoS₂ transistors display on/off ratios up to 10⁹_, leakage currents down to 10⁻¹⁴ A, and mobility of 33.4 cm²V⁻¹ s⁻¹. Oriented ionic channels facilitate efficient and controllable migration of Cl⁻ ions, thus realizing a non-structural-damage and reconfigurable transition between a quasi-metallic and semiconducting state in MoS₂, with a retention time exceeding 3000 s. During 100 cycles of state transitions, the quasi-metallic state exhibits a conductivity of 10⁻⁵ S, which is 10³ times that of the semiconducting state. Bio-inspired ionic channel further allows neuromorphic devices to integrate image storage, processing, and recognition capabilities, achieving a recognition accuracy improvement from 80.7% to 90.9% within just 5 training epochs through non-volatile preprocessing lasting over 300 s. Our study highlights the significant potential of this single-crystal ionic dielectric as a promising platform for fundamental research on electronic state modulation and advanced electronics.</p>