A bright line appeared on the display screen of a rugged display in air Electrostatic Discharge （ESD） 15 kV test. For the problem， an effective rectification method was proposed，which was to deal with the lap joint between the coated shielding glass and the shell of rugged display. It was included that：（1）The ITO film layer should be bare or have silver paste edge for the edge lap joint mode of the coated shielding glass， （2） The thickness of the conductive pads at the gap between the coated shielding glass and the shell of rugged display should increase in the case that the display effect could not be affected. The experiment results showed that： this method could make the rugged display pass the air ESD 15 kV test easily. It could also provide technical support for air electrostatic discharge design of subsequent rugged displays，showing important practical significance.