The invention discloses a method for realizing de-bonding through using flat-top nanosecond ultraviolet laser. According to the method, laser irradiates a bonding sheet with a light spot in flat-top distribution; a carrier, a release layer coating the carrier, an adhesive layer coating the release layer, a protective layer coating a wafer and the wafer are bonded together so as to form the bondingsheet; and the nanosecond ultraviolet laser irradiates the bonding sheet and breaks the bonds of a bonding adhesive, so that the bonding adhesive loses viscosity, and therefore, the bonded carrier and wafer can be separated from each other. With the method adopted, damage to the bonding adhesive can be avoided, de-bonding quality can be improved, and the processing efficiency of laser de-bondingcan be improved. The ultraviolet laser in flat-top distribution irradiates the bonding sheet, and therefore, the processing efficiency of the method is several times higher than the processing efficiency of a method adopting laser in Gaussian distribution.