A laser scanning device and a method using the same are provided. The laser scanning device includes a laser output unit, a shape rotation unit, a scanning unit and a control unit. The laser output unit is used to output a laser beam. The shape rotation unit is disposed on a propagation path of the laser beam for rotating a spot of the laser beam by a predetermined angle. The scanning unit receives the laser beam whose spot has been rotated by the predetermined angle to scan a work piece set on a carrier unit. The control unit is set between the shape rotation unit and the scanning unit for generating the predetermined angle based on a scanning position of the scanning unit.