The invention discloses a making method of preserved black jerusalem artichoke, and belongs to the technical field of food processing. The problems that in the existing preserved jerusalem artichoke production technology, preserved jerusalem artichoke is not suitable for glycosuria patients due to the fact that saccharose is exogenously added, and food safety is potentially affected due to the fact that sodium hydrogen sulfite and other food additives are added are solved. The processing technological process comprises the following steps of raw material freezing, sorting and cleaning, processing through zymogen, sealing, fermentation, drying, packaging, finished product forming and cold storage. Compared with raw jerusalem artichoke, in the preserved black jerusalem artichoke, the certain synanthrin content is reserved, the content of reducing sugar and polyphenols is obviously increased, a large number of melanoidins are produced, the product reserves the functions of regulating blood sugar in two ways, lowering blood fat, proliferating bifidobacteria, promoting mineral substance absorption, preventing and treating constipation, improving intestinal tract microenvironment, enhancing immunity, resisting cancer and preventing obesity of the synanthrin in the raw jerusalem artichoke to the certain degree, and the preserved black jerusalem artichoke has the stronger antioxidant function due to the fact that the content of the polyphenols and melanoidins is obviously increased.