The invention relates to a dendrobium officinale seedling cultivation device. The dendrobium officinale seedling cultivation device comprises a greenhouse and an air inlet device communicated with the greenhouse, wherein the air inlet device comprises an air pump, a hose, an elbow and a horizontal pipe, and the elbow comprises a high-position flat pipe, a middle-position flat pipe and a low-position flat pipe which are horizontally arranged and further comprises a first vertical pipe and a second vertical pipe which are vertically arranged; the middle-position flat pipe, the first vertical pipe, the low-position flat pipe, the second vertical pipe, the high-position flat pipe, the horizontal pipe and the greenhouse are sequentially connected; a spacer allowing the hose to penetrate through in a sealed mode is arranged in the first vertical pipe, the head of the hose is connected with the air pump, the middle of the hose extends along the middle-position flat pipe, the first vertical pipe, the low-position flat pipe and the second vertical pipe, and the tail of the hose is located in the second vertical pipe; the high position, middle position and low position are defined relative to one another. The invention further relates to a dendrobium officinale seedling cultivation method. A warm, moist, ventilating and sterile growth environment is provided for cultivating high-quality medicinal dendrobium officinale seedlings. The device and method belong to the technical field of seedling cultivation through plant tissue culture.