In order to realize the characteristics of large current, fast-rising speed, and high precision of High-intensity heavy-ion accelerator facility (HIAF) BRing dipole magnet power supply based on multi-module series-parallel structure, the digital controller of the power supply was required to provide more rapid and accurate acquisition, high-speed transmission, and complex operation capabilities, as well as more perfect fault detection and protection recovery mechanism. A new digital controller architecture was proposed, which consists of a core control board and a series of module power supply control boards. The module power supply control board is basically responsible for real-time acquisition, transmission and monitoring of the output state of each power supply module. The data read-back function which can improve the efficiency of power supply debugging was accomplished since the high-speed data interaction between module power supply control boards with the core control board was realized through the serial transceiver optical fiber. At the same time, a single-mode fiber loop is used to realize the synchronization sampling and communication fault monitoring mechanism of the whole controller system. And the software of the module power supply control board adopts a modular design idea and only uses hardware description language to realize the function of each module. After testing, the software of the module power supply control board not only meets the demand of power supply but also has good maintainability and expandability.