The present invention relates to a method and a device for producing sea sedge, capable of improving the taste of the sea sedge and preventing the sea sedge from rupture due to machining stress. The method for producing the sea sedge includes the following steps: washing raw sea sedge making the sea sedge in a plate shape to form plate-shaped sea sedge, heating and drying the plate-shaped sea sedge by a drying device, perforating the plate-shaped sea sedge by a perforating device, and baking the plate-shaped sea sedge by a baking device, wherein the plate-shaped sea sedge is perforated by more than two stages of perforating operations in a one-dimensional direction. In addition, as the perforating device, a part of a perforating rotating roller is stackedly provided with a plurality of disk-shaped perforating tools with jagged knife edges on the circumference.
