The invention provides a sulfur-fixing combustion-supporting high-temperature profile control agent, and a preparation method and application thereof. By taking the total weight of the sulfur-fixing combustion-supporting high-temperature profile control agent as 100%, the profile control agent is prepared from the following raw materials in percentage by weight: 3-5% of soft oil sludge, 2-4% of silicon sludge, 1-2% of low sulfur coal powder, 0.8-1.5% of sodium bentonite, 0.5-1.2% of plant fiber particle, 0.2-0.3% of saltpetre powder, 0.1-0.2% of coal gangue powder, 0.2-0.4% of limestone powder, 0.1-0.2% of polyanionic cellulose, 0.08-0.15% of alpha-sodium olefinsulfonate, 0.1-0.2% of sodium tripolyphosphate and the balance of water. The profile control agent has favorable stratum compatibility, causes no damage to the oil reservoir, does not pollute the stratum, and has favorable temperature tolerance; and meanwhile, the profile control agent has sulfur-fixing and combustion-supporting functions, thereby being completely applicable to a profile control technology for a thick oil fireflood chemical profile control gas injection well.