The invention provides a method and an apparatus for recovering oil substances in gas. The apparatus comprises a gas washing system, a cooling and recovery system and a tail oil recovery system. The gas washing system comprises a washing liquid pump and a separating column. The cooling and recovery system comprises a primary tube cooler, a primary gas-liquid separator, a secondary tube cooler, a secondary gas-liquid separator and a refrigerant fluid circulating pump. The tail oil recovery system comprises a tail oil recovery tank. According to the invention, through multistage separation, sectionalized recovery and cyclic refrigeration, the purpose of recovery of tar in raw gas is achieved; and the technical advantages of simple operation process, small equipment investment, low operation cost, a high recovery rate of tar, low consumption, energy conservation, environmental protection and the like are obtained.