The invention relates to a high-temperature-resistant compound oil-displacing agent for thermal recovery of thick oil. The oil-displacing agent is a water solution and comprises the following components in parts by weight: 0.001-20 parts of sodium salt and/or calcium salt of sulfonated phenol formaldehyde resin, 0.001-20 parts of non-ionic surfactant and/or non-ionic-anion surfactant for displacing oil, wherein the number-average molecular weight of the sulfonated phenol formaldehyde resin is 2000-200000; the mass percentage of sulfur in the sulfonated phenol formaldehyde resin is 5-20 percent. The oil-displacing agent has the advantages of no alkali, strong high-temperature resistance, good interfacial property, high viscosity-reducing rate and low cost.