The present invention discloses an egg yolk thin and crisp biscuit and a preparation method thereof. The egg yolk thin and crisp biscuit is characterized by preparing from the following raw materials in parts by weight: soybean curd dregs 200-210 parts, honey 5-7 parts, salted duck egg yolk 35-40 parts, corn flour 10-12 parts, platycladus orientalis kernels 2-3 parts, cerasus japonica kernels 1-2 parts, cistanche deserticola 2-3 parts, siraitia grosvenorii 4-5 parts, peanut oil 160-170 parts, egg liquid 180-190 parts, xylitol 100-105 parts, flour 100-110 parts, pea starch 20-22 parts, and mesona chinensis 10-11 parts. The main raw material of the soybean curd dregs are high in dietary fiber content, and the egg yolk thin and crisp biscuit is low in fat content compared to the commercially available biscuits, is suitable in protein content, is golden yellow in color and luster and good in appearance, is crisp in mouthfeel, is not sticky to teeth, can be used as a meal replacement food. The added mesona chinensis and the pea starch can form a gel to increase the cohesion of the biscuit, and the biscuit is intact and has no cracks in shape, is not easy to crack during the transportation and storage processes. At the same time, the mesona chinensis can avoid internal heat caused by eating too many biscuits, and in addition the egg yolk thin and crisp biscuit can moisten intestines.