The utility model provides a demountable lid plate -type air cooler pipe case of compact strenghthened type, include: manage the case body, including a plurality of wall casees, the pipe case passes through pass partition and separates into two or more wall casees, and each wall case is enclosed to close by apron, tube sheet, sideboard, pass partition and forms, and apron, tube sheet set up relatively, sideboard, the adjacent connection setting of pass partition, and the flange all integrates on each sideboard and the pass partition, a plurality of sideboard reinforcing plates are pressed close to the interior fixed surface of apron and are set up in sideboard edge, a plurality of tube sheet reinforcing plates are fixed in between tube sheet and the sideboard reinforcing plate.