Inner-atomizing development machine

The invention discloses a development machine capable of spraying inwards, which comprises a cutting device, a development machine body and an inward spraying device. A nozzle of the inward spraying device is arranged on the cutting device and comprises an inner pipe, an outer sheath and a fixing ring. The inner pipe is provided a shutter formed by arranging a plurality of fan-shaped valves inside. The circular arc end of each fan-shaped valve is hinged with the inner wall of the inner pipe; the fixing ring is fixed in the inner pipe and positioned on the inner side of the shutter. The outer sheath can be sleeved on the inner pipe in a sliding way; the front end cover of the outer sheath is provided with holes; and the outer sheathe is connected with the inner pipe through a spring. When the spring is in a free state, the fan-shaped valves are crushed into a smooth circular shutter by the front end cover of the outer sheath and the fixing ring. The nozzle of the inner spraying device opens only when spraying.