Power supply circuit of welding equipment and welding equipment

The utility model relates to the technology of inverter welding machines, and provides a power supply circuit of welding equipment and the welding equipment, and the power supply circuit of the welding equipment comprises a rectification filter circuit, a relay, a step-down rectification circuit, an inverter circuit, an auxiliary power supply, a buffer circuit, a control circuit and a driving circuit, the first output of the auxiliary power supply supplies power to the buffer circuit, the second output of the auxiliary power supply supplies power to the control circuit, the first output of the auxiliary power supply and the input negative electrode of the input power supply are in common ground, and the second output of the auxiliary power supply and the output negative electrode of the step-down rectifying circuit are in common ground. By arranging the power supply of the buffer circuit for driving the relay and the negative electrode of the input power supply to be in common ground, the coil of the relay an