The invention belongs to the technical field of aluminum alloy materials for electric power equipment and particularly relates to a method for manufacturing large-sized aluminum alloy bars with high strength and high electrical conductivity. The large-sized 6082 bars with high strength and high electrical conductivity, especially 6082T6 aluminum alloy bars with diameter from 150mm above to 300mm, are utilized for processing large-sized electrical elements with high strength and high electrical conductivity in the electric power equipment. An aluminum alloy ingot used in the method contains the following elements in percentage by mass: 1.0%-1.05% of Si, no more than 0.12% of Fe, no more than 0.10% of Cu, 0.55%-0.65% of Mn, 0.9%-0.95% of Mg, no more than 0.10% of Cr, no more than 0.10% of Zn, no more than 0.05% of Ti, no more than 0.05% of isolated impurity, no more than 0.15% of total impurities, and the balance being Al. According to the method, mass production and delivery can be achieved, the strength and the electrical conductivity of the large-sized aluminum alloy bars are enhanced, and processing and use are facilitated; the mechanical property and the electrical conductivity of the large-sized aluminum alloy bars obtained by the method are stable; in repeated operation, the bars can satisfy the Chinese standard of bars with diameter smaller than 150mm, the Chinese standard of bars with diameter from 150mm above to 300 mm can be supplemented or perfected and each performance index can be introduced into the Chinese standard.