The present invention discloses a method used in an optical disk drive for destroying data of an optical disk. The optical disk is rotated clockwise and the optical head moves one track per revolution. Then, the optical head is controlled so that the spot size of the emitted laser beam projected on the optical disk is about one track pitch wide and the laser beam has a destroy power. Thereafter, the laser beam with the destroy power is adopted to write the optical disk from the inner diameter to the outer diameter.