A polarity switching control method is provided for consumable electrode AC pulse arc welding. By the method, a peak current and a base current are applied during an electrode-positive polarity period, while an electrode-negative current is applied during an electrode-negative polarity period. For performing the welding, polarity switching is performed to alternate the electrode-positive polarity period and the electrode-negative polarity period. When a consumable electrode and a base metal are in short circuit with each other, the polarity switching is performed after the short circuit is broken and an arc is generated.