The invention discloses a low-temperature vacuum drying box which comprises a box body, a working chamber disposed inside the box body and a box door disposed outside the box body. The low-temperature vacuum drying box is characterized in that the working chamber comprises a drying plate, a first-kind drying frame for placing the drying plate, a retaining plate disposed below the top of the working chamber, a radiating coil disposed below the first-kind drying frame, a water retaining strip disposed at the bottom, close to the box door, of the working chamber, and a second-kind drying frame located below the first-kind drying frame. The low-temperature vacuum drying box has the advantages that the inner top of the working chamber is semi-elliptical, the structure with four arc corners allows temperature in the box body to be smooth and even during heating, in the meantime, steam drops generated by drying can flow from two sides into the central bottom of the box body and be pumped out by a vacuum pump via a bottom draining hole and a vacuum connecting pipe, and dryness in the box is kept all the time.