A lot of oil-based cuttings will be produced in the process of oil and gas exploration and development using oil-based drilling fluid. Without correct and efficient treatment, it is likely to cause serious environmental pollution and waste of resources. The oil-based drilling cuttings with high oil content (35.2 %) are treated by a chemical cleaning method in this study. An efficient cleaning agent (2.0 % Sodium dodecyl sulfate, 0.25 % Triton X-100, 0.86 %Na2SiO3, 5.0 % N-butanol and 91.89 % deionized water)is developed for oil removal. The results show that the efficiency of oil removal using the cleaning agent achieves 97.3 %. The soil-solid rate in drilling cuttings after treatment is 0.02. In addition, 3.5 % NaCl solution used to prepare the cleaning agent improves the efficiency of oil removal in the drilling cuttings and it provides a new idea and a guide for the direct use of seawater in treating oil-based drilling cuttings.