The invention relates to a method for processing oil sludge, and is suitable for processing ground crude oil in oil field, and a whole technology does not impacted by the loading. According to the existence state of oil, sand and water in oil-containing sludge, by the steps of heating, adding drug, homogenizing, aerating, depositing and centrifuging at high speed, the existence distribution state of oil, sand and water can be changed, the sand-in-oil phenomenon in the original oil sludge is gradually changed to sand-in-water, and the inclusion viscosity of the crude oil to sediment is reduced. Through settlement, oil sludge can be separated before entering into a centrifuge, the loading of the high speed centrifuge is reduced, processing amount of a device is increased, and the unit energy consumption is reduced. The separated sediment surface as well as the internal oil content are reduced to the lowest limitation. The unit treatment process parameter can be freely adjusted according to the oil-containing sludge processing requirement, the method has certain adaption capability; the process is simple and smooth, the operation and management are convenient, recovered crude oil and processed sediment can reach the standard in a stable manner, and a system employs the combination of automatic mode and manual operation.