The High Intensity Heavy-ion Accelerator Facility (HIAF) places high demands on the magnet power supply. In order to solve its special requirements, especially the high tracking accuracy, Analytic Modeling Optimal Control (AMOC) is proposed. To get the most suitable model of magnet power supply, its natural discreteness and continuity are considered and discussed in detail by comparing with other modeling methods. In addition, AMOC decomposes the power supply control problem into a single-cycle optimization problem. Compared with PI regulation, this method does not take time to manually adjust parameters with engineering experience. Facing different waveforms, its algorithm can control current to reach the reference value at the end of each cycle. These above characteristics are verified in the simulation. And on a quadrupole magnet power supply, the engineering feasibility of AMOC has been initially verified.