The invention relates to a preparation method for a novel red ginseng using reduced-pressure drying after high temperature high pressure process, also relates to the red ginseng prepared by the method, health functional food containing the red ginseng and red ginseng tea. Compared with common red ginseng, the novel red ginseng prepared by the method has the following features: contents of effective constituents like total phenol compound, maltol and ginsenoside are increased; color darkening phenomenon of the red ginseng is prevented, and the phenomenon is caused by a conventional method that high temperature high pressure process or repeated steaming and drying process are carried out to increase the effective constituent content; round ginseng state can be maintained; red ginseng with high extraction yield can be made in a short time; and the red ginseng can be smashed to make red ginseng tea powder, and the red ginseng tea powder can be used in warm water for fast releasing ingredients being beneficial to
