The invention discloses an aluminum machining device. The device comprises an outer fixing frame, an inner fixing frame, a grooving drill bit and a supporting plate; the outer fixing frame is erectedoutside the inner fixing frame, and the outer fixing frame is of a U-shaped structure; an air cylinder is fixedly arranged on the inner wall of the left side of the outer fixing frame, and a pointer and the grooving drill bit are arranged on a telescopic rod of the air cylinder; and the grooving drill bit is transversely and fixedly arranged at the rightmost end of the telescopic rod, and the right end of the grooving drill bit is attached to the left side surface of a cylindrical aluminum material. According to the device, the purpose of automatically grooving the aluminum material can be achieved through the cooperation of the motor and the air cylinder, the grooving mode of manually controlling a hand pressing block is replaced, so that the labor is saved, and the grooving efficiency isimproved; scales are arranged on the part, at the outer side of a sliding groove, of the inner fixing frame and the bottom surface of the part, below the pointer, of the outer fixing frame so that the grooving position and the grooving depth can be controlled through observing scales, and the precision is high; and in addition, the air cylinder controls the grooving drill bit to move, the grooving depth range is wide, and the device is suitable for popularization.