The invention relates to a recycling regeneration method and device for adsorbent for drying compressed air in a power plant. The device includes an air compressor, a precooler, a dust and oil removalfilter, an adsorption tower, a steam-water separator, a microwave generator, a PLC and an air storage tank. The method comprises the following steps: ambient air is sucked into the air compressor, hot compressed air discharged from the air compressor is initially cooled by the precooler, the cooled compressed air enters the dust and oil removal filter, when adsorption work is performed in an adsorption tower A, and after flow of the compressed air is uniformly divided through a perforated plate and a large amount of water is removed by the adsorbent, the dehydrated material is sent to the gasstorage tank under the condition that the dew point is qualified; at the time, the regeneration process of an adsorption tower B is started, the microwave generator is started, radiation heating is performed on the adsorption tower B, and a large amount of water molecules that are rapidly desorbed is heated, evaporated, and dried; at the same time, the dried and clean finished-product gas continuously flows into the adsorption tower B for purge regeneration, so that the regeneration process is completed; and the adsorption tower A and the adsorption tower B take turns to work to continuouslyprovide dried and clean compressed air.