The Oil Sludge of Liaohe oil field was cleaned and treated by hot water. The optimum reagent was selected by comparison, and the effect of experimental conditions (including the concentration of reagent, mass ratio of liquid to soil, stirring rate, slurry time and temperature) on oil yield were studied; and the best experimental conditions are obtained as follows: reagent concentration 4%, slurry time 25 min, slurry temperature 60 ℃, mass ratio of liquid to soil 4∶1 and stirring rate 200 r/min. Under these conditions, Oil yield can reach 94.29% after treating oil sludge once. The slurry solution can be recycled; the crude oil separated can be recycled after treatment.