The invention discloses an electrode core drying device. The electrode core drying device is characterized by comprising a drying oven, a heating device, a cooling device, a tray, a tray horizontal-moving device and a tray lifting and rotating device. An electrode core drying method includes multiple times of vacuum/inert gas-filled circulating, rotary heating, forceful cooling, exposure-free air butting and the like. By the electrode core drying device and method, inert gas is filled as heat conductive medium during heating, and heating speed is high; electrode cores are rotationally heated and subjected to forced convection, temperature uniformity is improved, and more reliable data are provided for heating temperature calculation. By the aid of vacuum and gas replenishing, water overflow is better facilitated, drying temperature of the electrode cores is lowered, and product quality is improved. During cooling of the electrode cores, cooling by inert gas and forced water cooling of a heating plate are realized, cooling time is greatly shortened, drying program is automatically controlled, the drying system is movable, a flange connector is directly abutted to a liquid injection tank through the drying oven, and secondary water absorption of the electrode cores is avoided.