A cathode roller internal conductive structure comprises a steel shaft and two supporting plates installed on the steel shaft in a sleeving mode, steel cores composed of copper layers and steel cylinders are installed on the excircles of the two supporting plates in a sleeving mode correspondingly, and a conductive copper sleeve and a copper plate with the diameter being equal to the diameter of each steel core are installed on the positions, on the outer sides of the two supporting plates, of the steel shaft from inside to outside correspondingly in a sleeving mode; and the copper plate covers the supporting plates and the steel cores, a copper disc is installed on the outer portion of the conductive copper sleeve in a sleeving mode, and a titanium cylinder is installed on the outer sidesof the steel cores and the copper plate in a sleeving mode. The cathode roller internal conductive structure has the advantages that high current is allowed, heat power consumption is low, electric-power lines on the roller surface of a cathode roller are even, and the cost is low.