The invention relates to novel coarse-food-grain biscuits and a preparation method thereof, belonging to the field of food processing. The coarse-food-grain biscuits are prepared through adding wheat flour, soda ash, vegetable oil, seasonings, additives and the like into vegetable pickled water and whole-grains flour, which serve as raw materials, so as to prepare flour dough, rolling the flour dough, so as to form flour straps, uniformly punching the flour straps, so as to form unbaked biscuits, carrying out two-stage low-temperature baking in a baker, then, cooling, and packaging. The coarse-food-grain biscuits and the preparation method thereof have the advantages that on one hand, the problem of utilization of the high-salt vegetable pickled water is solved, and the changing of resources into the valuable from the waste is realized; meanwhile, coarse food grains are taken as the raw materials, so that the biscuits are richer and more comprehensive in nutrition, the variety of the biscuits is enriched, the current concept of people on the pursuit of healthy living can be better met, and meanwhile, the market demands are met.