The invention relates to an offline large-area coating film production line, which comprises a reaction precursor liquid gasification system (9), a vapor phase deposition device (1) and a set of roller ways (4) which are matched with the vapor phase deposition device. The offline large-area coating film production line is characterized in that: the lower parts of the roller ways (4) are provided with waveform plates (2) of which the upper surfaces are provided with a set of semi-arc faces concentrically matched with the corresponding roller ways (4); a cover block (3) is positioned between the roller ways (4) respectively, and the two side edges of the cover block (3) are in clearance fit with cylindrical surfaces of the roller ways (4); and a quantitative gasification device (9) and a gas distribution device (7) are arranged in the gasification system. In the offline large-area coating film production line, the structure is simple, a film having one or a plurality of functions can beuniformly deposited on the surface of moving large-sized hot glass by adopting a proper gas precursor, and the film has a uniform thickness and no obvious optical interference fringes.