The invention discloses a device for separating a top electrode and a cooling disk. The device comprises a separating arm and an operating rod connected with the separating arm. When the top electrode needs to be maintained, the separating arm horizontally enters the mounting gap between the top electrode and the cooling disk at constant speed when an operator operates the operating rod so that the top electrode and the cooling disk can be separated. Because the operating rod and the separating arm are mechanically matched, the separating arm can horizontally enter the mounting gap between the top electrode and the cooling disk at constant speed, and therefore a tool does not need to be forcibly inserted into the mounting gap purely depending on brute force, human damage to the electrode is avoided, and meanwhile injury to the operator caused by sharp edges of the top electrode is avoided.