As the core component of arc welding technology, the performance of the arc welding power supply directly affects welding quality and efficiency. Aiming at the problems of high loss, large volume, and serious noise pollution in traditional industrial arc welding power supplies, this paper aims to develop a high-performance arc welding power supply solution. By adopting a symmetrical resonant network LLC(inductor-inductor-capacitor) resonant converter topology and combining it with high-frequency SiC(silicon carbide) power devices, a new arc welding power supply was designed. Through theoretical analysis, simulation verification, and experimental testing, the operating characteristics and noise reduction performance of the power supply were systematically studied. Experimental results show that the developed arc welding power supply prototype achieves an output power of 11 kW, a power density increased by about 300% compared with industrial-grade products, a peak efficiency of 96.3%, and effectively reduces operating noise. The external characteristics of the power supply meet the requirements of the arc welding process, and the system volume is significantly reduced. It can be seen that the new arc welding power supply design based on the LLC resonant converter and SiC devices can simultaneously achieve high efficiency, high power density, and low-noise operation, providing an effective technical path for the upgrading of industrial arc welding equipment.