reduction of electrolytic temperature and finally to a temperature of between 800 and 820 deg c since the corrosivity of the potassium cryolite kf alf 3 is stronger than that of the sodium fluoroaluminate in order to prolong the service life of the electrolytic cell the electrolytic cell needs to adopt an inert anode or a cathode subjected to inert surface treatment weighing 1 ton of aluminium and putting it into a reactor injecting argon to the reactor for protection after vacuumizing heating the reactor to a temperature of 800 deg c adding dried potassium fluotitanate in the reactor slowly in accordance with a reaction ratio and stirring quickly for 5 hours to form titanium sponge and potassium cryolite 3 2kf alf 3 opening the cover of the reactor pumping the superstratum melt liquid potassium cryolite 3 2kf alf 3 through a siphon pump adding the electrolyte supplement system 3 2kf alf 3 in the aluminium electrolysis process to the electrolyte basic system consumed continuously which can cause an obvious reduction of electrolytic temperature and finally to a temperature of between 820 and 850 deg c since the corrosivity of the potassium cryolite kf alf 3 is stronger than that of the sodium fluoroaluminate in order to prolong the service life of the electrolytic cell the electrolytic cell needs to adopt an inert anode or a cathode.