The invention discloses a cigarette box filling and sealing machine centralized box blank supply system and method. The method comprises the following steps that according to the specification and number of cigarettes needing to be produced by a cigarette factory, needed box blanks are placed on a transition conveying way; the box blanks are conveyed to a box blank to-be-transferred area through the transition conveying way; a crown rail and a hanging shuttle vehicle moving on the crown rail are arranged above the box blank to-be-transferred area and sealed boxes, and the crown rail constantlyextends to the position above a box filling and sealing machine from the position above the box blank to-be-transferred area in the length direction; the hanging shuttle vehicle grabs a certain number of box blanks from the box blank to-be-transferred area according to system instructions, and after elevating, the box blanks are moved to the positions above box blank material bins of the box filling and sealing machine; and the hanging shuttle vehicle places the box blanks into correct material bins according to the instructions and then returns to the box blank to-be-transferred area for thenext cycle, the box filling and sealing machine conducts butt joint on the corresponding material bins to the position of a box sealing feeding port according to instructions, and box sealing is conducted.