The invention discloses size-adjustable mold equipment for producing a plastic storage box. The size-adjustable mold equipment comprises a fixed mold and a movable mold. An injection molding runner isarranged on the fixed mold, and a box body cavity is formed in the movable mold; a plunger which is coaxial with the box body cavity and can penetrate through the box body cavity to move to the fixedmold is arranged above the movable mold, and the plunger is detachably arranged on a crossbeam; and an up-down driving mechanism is connected to the upper portion of the crossbeam. According to the size-adjustable mold equipment, the distance of a push-pull mechanism moving towards the middle is adjustable and can be controlled by an electric push rod or a starting push rod; and the plunger can be detached and replaced conveniently, and the plunger can be replaced with a plunger of the corresponding size and shape according to the external dimension of the storage box, so that the storage boxes of different sizes and dimensions are produced by one mold, one mold has multiple purposes, the mold opening time and cost are saved, and the production efficiency is improved.