In order to better deal with the oily sludge produced in the process of oil production, gathering and transportation as well as oil refining, and in line with the current development trend of environment⁃friendly chemicals in the petrochemical industry, it is very important to use environmentally friendly and low toxic and non⁃toxic chemical reagents in the neighborhood of sewage treatment. This paper introduces a new cleaning agent for oil sludge. Compared with the traditional cleaning agent, the new cleaning agent uses natural chemical derivatives (environmental friendly plant solvent is the main component), which has the characteristics of low toxicity, low pollution and high cleaning efficiency. The use temperature is 5~10 ℃ lower than the field use temperature, further reducing the use of energy. Under the synergism of composite cleaning agent, the residual oil rate in the cleaned sludge can be less than 2%, which has a wide and excellent application prospect.