A clamp is adopted in a drilling method of an airplane double-lug part and comprises a flat plate base, a drill jig plate, a positioning block, a lug piece support and a press plate module, wherein the positioning face of the positioning block is parallel to the main reference surface of the part, the lug piece support consists of a supporting shaft and two parallel supporting rings fixed to the supporting shaft, two ends of the supporting shaft are respectively fixed to the flat plate base and the drill jig plate, the part is clamped on a clamp, and the main reference surface of the part is arranged on the positioning face of the positioning block.