The invention discloses a production method of a vitamin B12 preparation. The production method mainly comprises the following steps: preparation of vitamin B12, vitamin B12-protein coordinate bonding, embedding, spray drying, granulation and packaging. According to the characteristic of high decomposition tendency of the vitamin B12, the vitamin B12 and protein are subjected to coordinate bonding, and embedded by using a protecting aid and porous starch, so that the vitamin B12 can exist stably, can be preserved easily, and can implement fixed-point high-efficiency release in the human body gastrointestinal tract digestion process.