Direct-current arc welding machine

The invention belongs to a direct-current arc welding machine with a direct-current arc starting power supply. The direct-current arc welding machine is a new generation direct-current arc welding machine for saving power and reducing materials and consists of a rectifying transformer, a rectifier or a controllable rectifier, a voltage doubling rectifying arc starting power supply and the like. The alternating-current input voltage, supplied to the rectifier or the controllable rectifier, of the secondary winding of the rectifying transformer is directly doubled and rectified to obtain a direct-current arc starting voltage required for arc starting. Therefore, the structure can be simplified and the secondary winding voltage of the rectifying transformer can be reduced so as to improve the transformation ratio and power factor of the rectifying transformer, reduce copper consumption and iron consumption of the transformer and fulfill the purposes of power saving and material reduction of the direct-current ar