The invention belongs to the technical field of machining, and provides a stacked slotted hole drilling machining method which is applicable to machining a stacked slotted hole formed through overlapping of a long slot and a short slot in the slot width direction. The method includes the following steps that with the tangent line passing through the end point of one side end of the short slot as a boundary line, the long slot is divided into two segments; with the boundary line as a boundary, first, the segment, abreast with the short slot, of the long slot is machined, then, the short slot is machined, and finally, the other segment of the long slot is machined so that the stacked slotted hole can be machined. According to the stacked slotted hole machining method, the long slot or the stacked slot is segmented, then, drilling machining is performed according to the corresponding sequence, and the phenomenon that burrs are generated on the joint between the long slot and the short slot is effectively avoided through the clockwise rotation of slot drilling and the resistance effect of a base material. According to the method, no cost needs to be increased, time and labor are saved, efficiency is high, and the slotting quality is good.