The invention provides a sea-buckthorn vinegar preparing method. The method comprises the steps of material selection, starter propagation, smashing, steaming, saccharification and alcoholic fermentation, acetic fermentation, vat fuming, red vinegar sprinkling, curing, finished vinegar sprinkling and ageing. According to the method, solid anaerobic airtight fermentation is conducted, and various microorganisms coexist; in the co-fermentation and fermentation process of various enzyme systems, mould, saccharomycetes and acetic bacteria coexist, various enzyme systems including liquefying amylase, saccharifying amylase, cellulose, pectinase, zymase and acetification enzyme are adopted for co-fermentation, the color, aroma, taste and appearance of vinegar are good, concentration is high, clarity is high, and main physicochemical indexes including total acid, non-volatile acid and revertose are excellent.