The utility model discloses an edge folding device for carton processing, and relates to the technical field of carton processing. The device comprises a base, one surface of the base is fixedly connected with a pre-pressing gluing mechanism and an edge folding mechanism. The pre-pressing gluing mechanism comprises a support frame; a conveying assembly is fixedly connected between the inner surfaces of the supporting frames. One surface of the support frame is fixedly connected with two groups of adjustable pipe clamps and a fixing frame respectively; one end of the adjustable pipe clamp is fixedly connected with a guide plate; the top of the fixing frame is fixedly connected with two first cylinders. By optimizing the edge folding process of the pre-pressing gluing mechanism, the edge folding mechanism and the overturning assembly, on one hand, pre-pressing is conducted before edge folding, and the problems that edge folding lines are prone to deflection in a traditional direct edge folding mode, and then the edge folding forming rate is reduced are solved; and meanwhile, the gluing device and the paperboard move relatively, so that the gluing uniformity is guaranteed, and meanwhile, the gluing length requirement of the carton can be met.