The invention provides a vacuum drying device. The device comprises an accommodating box body, a gas passage structure and a vacuumizing pump, wherein at least two surfaces of the accommodating box body are respectively provided with an air exhaust port; the gas passage structure comprises a plurality of interface connecting parts, and each interface connecting part is respectively connected withone exhaust port; and the vacuumizing pump is connected with the gas passage structure, communicates with the accommodating box body through the gas passage structure, and can vacuumize the accommodating box body. By adopting the vacuum drying device, the air in the accommodating box body can be extracted from different positions of the accommodating box body by arranging the air exhaust ports inat least two surfaces of the accommodating box body respectively, so that the uniformity of the distribution of the solvent in the accommodating box body in the drying process of a to-be-dried substrate is ensured, and the problem of uneven film thickness caused by different solvent atmospheres in the central area and the edge area of the to-be-dried substrate due to too high local concentration is avoided.