Black ginseng is a novel manufactured ginseng product, and the application of black ginseng products in market is increasing in recent years. Black ginseng is prepared by steaming and fermentation, but not as mature as processing red ginseng. Therefore, complete proposals for preparation techniques are firstly presented. Additionally, there are also abundant chemical components in black ginseng, including ginsenosides, polysaccharides, amino acids, polyphenols, flavonoids, etc. Among them, ginsenosides, polysaccharides and phenolic compounds are the main ingredients, making health benefits of black ginseng stronger than other ginseng products. Therefore, black ginseng as a functional food has come to the market in various forms, such as candies, tea, porridge, soup, etc. The improvement in nutrition, flavor, and safety has exhibited a broad prospect for black ginseng products in food industry. Accordingly, preparation technologies, phytochemistry, health benefits and application of black ginseng are comprehensively evaluated.