The invention relates to a drying process method of a specific plant. The method comprises the following steps of: (1) pretreatment: sorting and selecting prepared fresh pseudo-ginseng, separating and removing snips, fibrous roots and flocking roots attached to the fresh pseudo-ginseng roots to obtain pseudo-ginseng main roots, cleaning and removing surface attachments, draining surface moisture, and cutting into 0.2-2 mm slices by using a slicing machine; (2) pre-freezing: directly placing the slices in a pre-freezing room with the set temperature of subzero 15 to subzero 20 DEG C, and pre-freezing for 5-6h; (3) sublimation drying: spreading the pre-frozen slices out on a desk tray made of a conducting material, controlling the spreading thickness to be below 5 cm, and moving to a vacuum drying room; sealing, starting vacuumizing, maintaining the internal vacuum pressure at 30-70 pascals, setting the temperature of the desk tray to be 40 DEG C, keeping supplying heat for the desk tray, and carrying out vacuum sublimation drying for 7-10h until the temperature of the desk try reaches 40 DEG C; (4) analysis: maintaining the temperature of the desk tray to be 40 DEG C, keeping supplying heat for the desk tray and vacuumizing for 6-12h until the temperature of the material reaches 40 DEG C, and controlling the moisture of the material at 3-5%; and (5) discharging and packaging.