The invention discloses a device for producing paper boxes. The device comprises two conveying units. Each conveying unit comprises a support, a movable plate and a lead screw. Each support is provided with a guide rail distributed horizontally. The guide rails on two work tables are parallel. Each movable plate is movably connected with the corresponding guide rail. The upper surface of each movable plate is provided with multiple containing grooves at intervals in the length direction of the corresponding guide rail. The length direction of each containing groove is perpendicular to the length direction of the corresponding guide rail. The lower surface of each movable plate is provided with an external gear. The two movable plates are parallel. Each lead screw is rotationally connected with the corresponding support. The first end of each lead screw is arranged below the corresponding movable plate. Each lead screw is engaged with the corresponding external gear. The second end of each lead screw extends in the direction of being close to the other conveying unit. The device for producing the paper boxes is simple in structure and good in cutting effect.