The invention relates to a device for facilitating energy-saving operation of a paperboard production line and a control method of the device. The device comprises a lifting paperboard piling mechanism, the lifting paperboard piling mechanism is provided with a paperboard piling conveying table which conducts lifting movement, and the paperboard piling conveying table is provided with an outlet end and an inlet end connected with the paperboard production line. The device further comprises an auxiliary lifting paperboard conveying mechanism which is arranged beside the outlet end of the lifting paperboard piling mechanism. When the paperboard piling height is changed, the auxiliary lifting paperboard conveying mechanism ascends to a proper height and receives paperboard piles discharged by the lifting paperboard piling mechanism in time so that the lifting paperboard piling mechanism can rise to the initial paperboard receiving height again in time, and constant-speed operation of the paperboard production line is guaranteed. The device is simple and reasonable in structure, convenient, safe and reliable to operate, and beneficial for prolonging the service life of the paperboard production line and reducing energy consumption.