Abstract: A method of machining holes on a metal plate contains steps of: providing a metal plate and an auxiliary working sheet; contacting the auxiliary working sheet with a first face of a drilling area; drilling a hole on the auxiliary working sheet and the drilling area; and removing the auxiliary working sheet from the drilling area. The metal plate includes the drilling area, and the drilling area has the first face and a second face opposite to the first face, a hardness value of the auxiliary working sheet is 0.7 times more than the metal plate, and a rotating speed of a driller is more than 8,000 rpm/min, thereby machining the hole on the metal plate smoothly and uniformly.