The invention provides a high-power SiC submerged arc welding power supply. The high-power SiC submerged arc welding power supply is characterized by comprising at least one main circuit and digital control circuit; each main circuit comprises an electromagnetic noise inhibition module, a power frequency rectification filter module, a SiC inverse transformation current module, a high-frequency power transformer and a high-frequency quick rectification smooth module connected in sequence; the high-frequency quick rectification smooth module is connected with an arc load; the digital control circuit comprises a DSC control system, a human-computer interaction module, a safety protection module, an ultrahigh-frequency driving module and an electric signal detecting module; the ultrahigh-frequency driving module is connected with the SiC inverse transformation current module; the safety protection module is connected with the SiC inverse transformation current module; and the electric signal detection module is respectively connected with the high-frequency power transformer and the high-frequency quick rectification smooth module. A SiC power switch tube can be applied to the submerged arc welding power supply, so that the inversion frequency is greatly improved, the efficiency is high, the size is small, and the welding quality is improved.