The invention relates to a welding power supply device with low impact load. The welding power supply device comprises a three-phase rectification circuit module and a welding output unit; the welding output unit includes a welding power supply output module, a welding tool, an arc striking auxiliary device, a welding auxiliary device and a thyristor I; and the three-phase rectification circuit module is connected with a three-phase alternating-current power supply. The welding power supply device with low impact load enables the welding tool to obtain arc striking voltage higher than the voltage, of a direct-current power supply, output by the three-phase rectification circuit module through the arc striking auxiliary device, and enables a welding capacitor to output welding current with the welding power supply output module through the welding auxiliary device when the welding tool normally welds, and greatly reduces the impact load of a power grid.