The invention relates to a treating method for oil-containing pebbles in an accident oil pool of a transformer. The treating method comprises the steps that (1) a microemulsion-type cleaning agent is prepared, specifically, APG1214 and peregal 30 are prepared into a compound nonionic surfactant in accordance with the mass ratio of 8:2 to 6:4, then NaCl salt water is added, a cosurfactant, namely n-butanol, is added, and the microemulsion-type cleaning agent is obtained, wherein the microemulsion-type cleaning agent comprises, by weight, 10%-20% of the compound nonionic surfactant, 2.5%-5% of the cosurfactant, and the balance 5% of the NaCl salt water; (2) the cleaning agent is added to the oil-containing pebbles to be stirred fully in accordance with the mass ratio of 3:1; and (3) washing liquid after cleaning is discharged, solid liquid separation is conducted, and an upper layer oil phase is recycled after centrifugation. According to the treating method for the oil-containing pebbles in the accident oil pool of the transformer, the cleaning agent has long-term stability, the cleaning technology is simple and easy to conduct, cost of equipment and materials is low, and the social value and the economic value are great.