The nutrients in vegetables mainly contain minerals, vitamins, fiber and so on, the higher the content of these substances, the higher the nutritional value of vegetables. In addition, the content of water and dietary fiber in vegetables is also an important indicator of nutritional quality. Usually, vegetables with high water content and low dietary fiber have better freshness and higher food value. However, from a health care perspective, dietary fiber is also an essential nutrient. The nutrients of vegetables should not be underestimated, in 1990, the International Food and Agriculture Organization of the statistics of the human body essential vitamin C 90%, 60% of vitamin A are from vegetables, vegetables can be seen on the human health of the contribution of the huge. In addition, vegetables have a variety of phytochemicals are recognized as beneficial to human health components, such as carotenoids, dipropylene compounds, methyl sulfide compounds, etc., many vegetables also contain unique trace elements, the human body has a special health effects, such as tomatoes in the lycopene, onions in the prostaglandins.