The invention discloses a monosodium glutamate flavoring agent adopting edible fungi. The flavoring agent is composed of the following raw materials in parts by weight: 15-22 parts of animal bones, 6-13 parts of hericium erinaceus, 12-18 parts of plant proteins, 8-18 parts of ganoderma lucidum, 10-15 parts of bolete, 0.1-0.3 part of alkaline protease, 0.4-0.8 part of cyclodextrin, 4-8 parts of Chinese wolfberry fruits, 0.3-0.6 part of a stabilizer, and 2-5 parts of starch. The invention also discloses a preparation method of the monosodium glutamate flavoring agent. The invention has wide sources of raw materials and simple preparation processes, and is suitable for large-scale industrial production. According to the invention, nutrient components of a plurality of raw materials are extracted in different ways, and the prepared finished products not only have a good taste, but also rich nutrients. Meanwhile, the flavoring agent satisfies people's nutrient needs and taste needs, and has a wide market prospect.