The utility model provides a safe cutting tool who decomposes impact stress, including the side surface opening be the cavity structure the worker's stadium, set up at the inside a plurality of cuttings piece of the worker's stadium, the cutting piece is including elevating gear and set up the cutter in the elevating gear upper end, the edge of cutter is the blade of cockscomb structure, adjacent blade be equipped with within a definite time to slot, the slot end of blade center extension be provided with with the communicating hole of cuting of slot. The utility model discloses in, the slot seted up between adjacent blade and make impact stress that the cutter received transmit for cuting the hole along the slot with the slot terminal communicating hole of cuting cuts the hole and with the resolution of stress, avoids comparatively concentrating the rupture because of the blade atress.