The invention discloses a wheat composite flour and a preparation method thereof. The flour is prepared from the following raw materials in parts by weight: 200-300 parts of whole wheat flour, 10-15 parts of japonica rice, 5-8 parts of betel nut taro, 6-10 parts of sargassum fusiforme, 6-8 parts of balsam pear, 5-10 parts of green money willow, 2-3 parts of hairyvein agrimonia herb and bud, 1-2 parts of sunflower leaves, 1-2 parts of a snakegourd fruit powder, 2-3 parts of cactus flowers, 1-2 parts of ginseng flowers, 2-3 parts of folium mori, 1-2 parts of potentilla discolor bunge, 2-3 parts of pumpkin vines, 5-8 parts of tremella powder, 4-6 parts of lentil and 3-6 parts of cucumber seed powder. The flour provided by the invention contains nutritional ingredients such as the betel nut taro, the green money willow and the like and has the effects of enriching nutrition, tonifying and nourishing the kidney, strengthening the spleen, nourishing the stomach, and reducing blood pressure and cholesterol, and is beneficial to people's physical health; moreover, various beneficial ingredients of traditional Chinese medicines are added into the formula; the compatibility is reasonable, the efficiency of health protection is enhanced, the processed wheat flour food is enabled to have the functions of easy digestion and absorption, and the cholesterol and blood pressure are lowered.