The invention discloses compound 
dietary fiber powder and a preparation method thereof. The compound 
dietary fiber powder is prepared from the following components in parts by weight: 20 to 80 parts of 
dietary fiber, 50 to 80 parts of 
sorbitol, 4 to 20 parts of 
potassium citrate, 0.5 to 5 parts of 
citric acid, 0.5 to 5 parts of 
silicon dioxide, 0.1 to 3 parts of 
magnesium oxide and 0.5 to 5 partsof auxiliary materials, wherein the sum of the components is 100 parts; the auxiliary materials comprise green lemon primary pulp 
powder, psylliumseedhusk powder, 
malic acid, 
calcium hydrogen phosphate, 
fructose-
oligosaccharide, oat powder and 
inulin. According to the compound dietary 
fiber powder and the preparation method thereof disclosed by the invention, by taking the 
efficacy of natural plants as an action mechanism, 
plant raw materials can be eaten and have no harm to the health of a 
human body; a main action principle of the compound dietary 
fiber powder is characterized by regulatinglipid 
metabolism, promoting human detoxification, and conditioning 
digestion and absorption functions. The compound dietary 
fiber powder disclosed by the invention has the advantages that the absorption of fat in a 
digestive tract can be effectively limited, the 
excretion of lipoid is promoted, an intestinal environment is adjusted, good 
bacteria advantages are created and intestinal tract movement is accelerated to 
discharge wastes.