The invention relates to a wall-through hole structure of a gas insulated switchgear (GIS). The structure comprises a GIS line pipe and a wall-through reserved hole and is characterized in that a spoon-shaped steel plate is arranged at an inner side of the wall-through reserved hole, a sealing inner plate is arranged in a part, near to the outdoors, in the wall-through reserved hole and is arranged in the spoon-shaped steel plate, a heat preservation and weather resistant layer is arranged between the sealing inner plate and an outdoor wall of the wall-through reserved hole and between the GIS line pipe and the spoon-shaped steel plate, a heat preservation and weather resistant layer is also arranged between the spoon-shaped steel plate and the wall-through reserved hole, a waterstop steel plate is arranged in a gap between the heat preservation and weather resistant layer and the GIS line pipe in an annular way, the waterstop steel plate extends towards the outdoors from the gap along the GIS line pipe to form an extension part, and an end part of the extension part of the waterstop steel plate is fixed on the GIS line pipe by a steel stranded wire. The structure has the advantages of heat preservation, fire resistance and a waterproof function, and is rapid to install and convenient to maintain.