Disclosed are a method and system for magnifying and displaying local image of a touch display device. When an object is detected to be approaching an effective touch zone on a touch surface of a touch panel, the distance or altitude between the approaching object at a position on the effective touch zone of the touch panel where the approaching object heads for and the touch surface of the touch panel is determined. When the distance is less than a first predefined approaching altitude, a target graphic representation associated with the position of the approaching object on the touch panel is first enlarged and then, based on a second predefined approaching altitude, an operation of magnification of the local area or the target graphic representation displayed on a display panel corresponding to the position of the approaching object or execution of an executable object linked to the graphic representation is carried out. The second predefined approaching altitude can be defined as being in contact with the touch surface of the touch panel.