The invention discloses a method for controlling a cathode cleaning area in the aluminum alloy welding process. The method is characterized in that during aluminum alloy electric arc welding, when a to-be-welded workpiece is connected with a cathode, three beams of lasers acting on the front face and the two sides of a molten pool correspondingly are adopted for adjusting the range of the cathodecleaning area. According to the method, the width and the cleaning range of the cleaning area can be freely controlled, and damage of too large or too small cathode spot dancing to welding quality isavoided; during corner joint, the cleaning area can be prevented from deviating to a certain side through laser guide; and the requirement for the laser power density is low, and the effect of guidingcathode spots can be achieved through the low-power lasers being about 300 W.