Using self-developed super-capacity switching power supply digital power amplifier. Compared with open-loop or semi-closed-loop control methods, compound feedback control can greatly reduce the influence of power fluctuations, switching devices and LC filter errors and non-idealization, so that key technical indicators such as distortion, frequency response, and damping coefficient can be greatly improved. The amplitude is improved and the hearing performance is perfect. The switching power supply is optimized and designed according to the working characteristics of the audio amplifier, with strong power, quick response and little interference to audio signals. In addition to multiple protection circuits such as short-circuit, over-current, over-temperature, and ultra-high frequency, it also pays attention to humanized design to facilitate operation and prevent possible misoperation.