The invention discloses weight-losing meal replacement powder which is prepared from the following raw materials: protein power, fruit powder, dietary fibers, plant powder, a sweetening agent, a taste improver and water soluble vitamins. The preparation process comprises the following steps: performing material acceptance, burdening, mixing, performing sterilizing treatment, performing quantitative packing, checking, boxing and warehousing. The weight-losing meal replacement powder prepared according to the invention is low in calorie and high in satiety and is capable of supplementing high-quality proteins, vitamins, mineral substances and dietary fibers, so that balanced diet is realized. Meanwhile, due to the addition of fatty taste improver, good taste can be maintained. Moreover, the body weight can be reduced while enjoying delicious foods, so that an excellent physical state of the human body is maintained.