The invention provides a wafer adsorption mechanism, wherein an adjusting bottom board is arranged between a mounting disk and a basal disc, wherein, edges of the bottom of the adjusting bottom board are symmetrically distributed with raised grooves, side edges of the adjusting bottom board are evenly provided with fastening screws, the center of the adjusting bottom is provided with a centre bore of the adjusting bottom board, a long air duct and a short air duct which are crossed at the centre bore of the adjusting bottom board, wherein, the upper wall of a screw hole of the long air duct is provided with a larger annular adjusting hole, the upper wall of a screw hole of the short air duct is provided with a middle annular adjusting hole; the large annular adjusting hole fitly connected with a short adjusting screw nut and a short adjusting component, the middle annular adjusting hole is fitly connected with a long adjusting screw nut and a long adjusting component, screw outer rings of the long adjusting component and the short adjusting component are provided with pistons and seal rings. The basal disc is made of porous ceramic materials, wherein, the internal bottom surface of the basal disc is provided with a centre hole of the basal disc, a concentric ring air duct groove, a large ring compress hole, an inter-ring air duct and a middle ring compress hole, the outer ring of the internal bottom surface of the basal disc is pasted with a large vacuum ring, and the middle ring of the internal bottom surface of the basal disc is pasted with a middle vacuum ring, and the center of the internal bottom surface of the basal disc is pasted with a small vacuum disk, and the install disk and the adjusting bottom board are tightly connected. The mechanism can adsorb 3 to 8 wafers only through simple adjustment.