The invention discloses a back coating type double-station laminating machine and a working method thereof. The machine is technically characterized by comprising a paper unwinding unit, a film unwinding device, a coating and laminating unit, a drying box, a stripping unit, a film winding unit, a lustering unit, a backing coating unit, a paper traction unit and a paper winding unit, wherein the paper unwinding unit is used for outputting paper, the film unwinding device is used for outputting films, the coating and laminating unit is used for coating and laminating the paper and the film intocomposite paper, the drying box is used for drying the composite paper, the stripping unit is used for stripping the composite paper dried by the drying box, the film winding unit is used for receiving the stripped film, the lustering unit is used for further processing the composite paper with the film stripped off, and the back coating unit is used for carrying out back coating on the lustered composite paper. According to the machine, the paper unwinding unit and the film unwinding device adopt a double-station zero-speed butt joint material changing technology, the whole machine can realize high-speed continuous production of 200meters/minutes without halt, roll changing does not require speed reduction or halt, continuous operation can be realized at a constant production speed, and the production efficiency and the finished product rate of products are greatly improved.