Abstract: With waste oil-refining catalyst as raw materials，sulfuric acid，hydrochloric acid，and nitric acid three different kinds of acid were employed to dispose waste oil-refining catalyst containing high heavy metals，such as nickel.Contents of five heavy metals including Ni，Hg，Pb，Cr，and Cd were determined by flame atomic absorption spectrometry.The optimum technological conditions of separation of harmful heavy metals from oil refining waste catalyst were discussed.Results showed that，under the calcining temperature of 400 ℃，calcining time for 3 h，mass fraction of sulfuric acid was 10%，the volume ratio of liquid to solid was 5∶1，and extraction time was 5 h，extraction rate of Ni，Hg，Cr，Pb，Cr，and Cd were the best.

Key words: waste oil-refining catalyst, heavy metal；separation