Sweet potato powder is rich in dietary fiber, carotene, vitamins A, B, C, calcium, iron and other nutrients, which is helpful to promote intestinal peristalsis, prevent constipation and maintain normal metabolism and health of human body. Sweet potato powder can also be used as a low-calorie, low-fat and high-fiber food choice, which is suitable for people who lose weight and exercise. Alfalfa powder is also rich in protein, dietary fiber, vitamins and minerals, but its main functions are clearing away damp-heat, moistening lung and relieving cough, promoting diuresis and removing stones. It is suitable for treating damp-heat diarrhea, dysentery and jaundice. According to the comparison of nutritional components and efficacy, sweet potato powder provides a variety of nutritional elements more comprehensively and has a wider scope of application, so sweet potato powder is better.