Aluminum alloy welding method

The invention provides an aluminum alloy welding method. According to the aluminum alloy welding method, a laser beam and a plasma arc are adopted to form a combined heat source to act on aluminum alloy to conduct welding, the plasma arc is alternately generated by two heteropolar electrodes, the straight line where the output center axis of the plasma arc is located coincides with the straight line where the output center axis of the laser beam is located, and according to the aluminum alloy welding method, plasma gas is fed in a square wave pulse mode. According to the aluminum alloy weldingmethod, the plasma gas is fed in the square wave pulse mode, and therefore molten metal in a molten pool can be prevented from splashing, and the negative interference cannot be introduced in the welding period. Besides, periodic oscillation synchronous with the plasma gas pulse period is generated in the molten pool in the welding process of the aluminum alloy welding method, rising of bubbles in the molten pool is prom