The invention discloses a full-nutrition dietary fiber solid beverage and a preparation method thereof, and relates to the technical field of health food. The full-nutrition dietary fiber solid beverage is prepared by: using Chenopodium quinoa Willd powder, collagen peptides, chia seed powder, beta-glucan, white kidney bean powder and oats as main components, and compounding the main components with various dietary fibers including barley and other grains, fruits, vegetables, etc., traditional Chinese medicinal materials with homology of medicine and food including cassia seeds, barbary wolfberry fruits, etc. and nutrient components including vegetable proteins, skimmed milk powder, compound minerals, compound vitamins, etc. Therefore, the full-nutrition dietary fiber solid beverage is balanced and reasonable in nutrient component composition, good in satiety feeling, good in effect, quick to tale effect, ready-to-eat once preparing, good for absorption of the human body, beneficial tohelp people shape the body and capable of meeting people's demands for a perfect figure very well.