The invention belongs to the field of water glass used sand regeneration and sewage treatment and discloses an alkaline sewage recovery method for wet regeneration of water glass used sand. The method comprises the following steps of: pre-treating the water glass used sand in a treatment pond; then eluting and dehydrating the water glass used sand for many times to obtain regenerated sand and sewage; detecting whether the content of Na2O is lower than a preset value or not; if the content of Na2O is lower than the preset value, performing drying to regenerate the water glass used sand; if the content of Na2O is higher than the preset value, scrubbing and regenerating the regenerated sand, and dehydrating the regenerated sand again and drying the same, wherein high concentration alkaline sewage removed several times before returns to the treatment pond till the alkalinity of the solution in the treatment pond is greater than an alkalinity preset value; and at the moment, the high concentration alkaline sewage in the treatment pond is extracted, and the high concentration alkaline sewage removed several times is supplemented to the treatment pond for regenerating the used sand continuously. According to the method provided by the invention, under relatively small water consumption, high quality regenerated sand can be obtained, and most alkaline substances can be recovered from the regenerated sewage.