The disclosure provides a process for preparing an inert anode material or inert cathode coating material for aluminium electrolysis, which includes the following steps: A) putting aluminium into a reactor, injecting an inert gas to the reactor after vacuumizing, adding the mixture of dried fluoborate and fluorotitanate in the reactor to enable a reaction to form titanium boride and cryolite, and isolating the titanium boride; and B) melting the obtained titanium boride with a carbon material, tamping the melt liquid on a carbon cathode surface, sintering the carbon cathode surface to form the inert cathode coating material for aluminium electrolysis; or, mixing the obtained titanium boride with the carbon material evenly, then high-pressure moulding the mixture, and finally sintering the moulded mixture at a high temperature to form the inert anode material for aluminium electrolysis.