Nowadays surfactants were used to wash oily sludge and reclaim oil. This paper presents the optimum conditions for washing oily sludge with surfactant solutions using the single factor experiment. The agents tested are AEO-9, Peregal O, TritonX-100, sodium metasilicate and sodium dodecylbenzene sulfonate (DBS). In the experiments, four factors affecting residual oil rate are investigated which include liquid/solid mass rate, reaction temperature, reaction time and eluent mass fraction. Results obtained through experimental runs were compared and used to select a kind of agent, in order to get the best cleaning effect. The optimum parameters of these agents are different from others, and under the optimum conditions their treatment effects are better. And the washing effect of Na2SiO3·9H2O is best and its residual oil rate is only about 1.6%.