Abstract: This paper selects a toroidal-core AC inductor as the research object. Focusing on magnetic core saturation, high-frequency winding loss, and coil design constraints under operating frequencies from tens of kilohertz to several hundred kilohertz, a MATLAB-based two-dimensional grid numerical calculation method combined with magnetic circuit approximation is adopted to analyze the influence of current magnitude and excitation frequency on the design of the magnetic core and coil. The model calculates the magnetic flux density distribution on the two-dimensional cross-section of the toroidal core, and carries out parameter scanning by considering skin depth, AC-to-DC resistance ratio, copper loss, and core loss. The simulation results show that, under the assumed parameters for this coursework, the maximum flux density of the original design reaches at 10 A, which is close to , indicating a relatively high saturation risk. After reducing the effective permeability by introducing an equivalent air gap, the maximum flux density of the improved design decreases to at 10 A, and the saturation risk is significantly reduced. Meanwhile, an increase in frequency leads to a decrease in the skin depth of the copper wire, an increase in and increases in both winding copper loss and core loss. The results indicate that the design of high-frequency high-current AC inductors should comprehensively consider magnetic core saturation, high-frequency effects in the coil, losses, and thermal constraints.