The invention relates to a seaweed sauce and a method for preparing the same. The seaweed sauce is prepared from mixing seaweed seasoning fluid and high salt diluted sauce according to the volume ratio of 1:(1-2) and then adding auxiliary materials to mix and process, wherein the auxiliary materials comprise salt, yeast extract, maltose, disodium 5'-ribonucleotide, sodium glutamate and edible alcohol. The auxiliary materials are mixed according to the steps that the salt, the yeast extract and the maltose are sequentially added, the yeast extract and the maltose are dissolved to be heated to boil, monosodium glutamate and the disodium 5'-ribonucleotide are then immediately added, the mixture is dissolved and then stood at normal temperature, and the edible alcohol only needs to be added. The adopted seaweed resources are rich and low in cost, the method for preparing the sauce is simple and is more suitable for industrialized production, the fishy smell of the seaweeds is completely removed, moreover, the sauce has a slight jasmine aroma, high nutritional value and no added preservatives, and the seaweed sauce which is mixed with the seaweed seasoning fluid has a more fresh flavor. Obviously, the effective method and a new approach are provided for the high-valued seaweed utilization.