The invention discloses an energy-saved flow stabilization construction method of a large prebaked tank. The method comprises assembly of a cathode superconductivity flow stabilization steel rod and a cathode carbon block, and building of an electrolytic cell lining material; a center line of the cathode superconductivity flow stabilization steel rod is matched with a center line of a dovetail groove of the cathode carbon block; the deviation of total length of the cathode superconductivity flow stabilization steel rod after assembly is 3810+-5 mm; and the electrolytic cell lining structure includes the following parts from the surface of a baseplate in sequence: a calcium silicate board, vermiculite thermal insulation bricks, a novel superstrong insulation impermeable thermal insolating layer, two layers of vermiculite thermal insulation impermeable bricks, installation of an assembled cathode carbon block set, vibration of impermeable castable between two ends and the steel rod, building of refractory bricks, building of side blocks and final actuation of carbon-carbon pasting and surrounding pasting fixation. The method prominently improves the whole furnace casting process level of an electrolytic cell, obviously reduces the furnace bottom pressure drop, prominently improves the electric conductivity, obviously enhances the insulation performance of the furnace bottom and the side part of the electrolytic cell, is excellent in whole insulation effect of the electrolytic cell, obviously reduces the direct-current working voltage, and obviously improves the comprehensive alternating-current power consumption index.