The invention discloses a cathode soakage device. The baked cathode is sent to a preheating oven to preheat to 260 deg C to 320 deg C firstly, then the preheated cathode is sent to a high-pressure soakage tank to pressurize by air(0.5 MPa) for 5 to 15 minutes and to pressurize by nitrogen (1 to 2 MPa) for another 3 to 5 minutes, molten asphalt is pressed in and fills up pores in the cathode by high-pressure gas. The cathode soakage device comprised a preheating oven and a high-pressure soakage tank, a push feeder is installed in front of the preheating oven, a basket-for-plane is placed behindthe preheating oven, orbit is installed between the basket-for-plane and the high-pressure soakage tank,cathode carriers is on the orbit, a fixed-track machine is also installed in front of the high-pressure soakage tank. As a result of the above-mentioned process, the baked cathode is used in the electrolytic aluminum processing after soakage, so the weight of cathode is greatly improved, indirectly improving the quality and production efficiency of electrolytic aluminum product.