Abstract: Oily sludge treatment is one of important environmental protection issues in petroleum industry. Oily sludge harmless disposal and recycling treatment technology becomes the focus of research in recent years. The conventional and new technologies of oily sludge harmless disposal and recycling treatment in recent years are summarized in this paper, the advantages and disadvantages of various treatment technologies are contrastively analyzed, and the Chemistry-Biology joint treatment technology will become the main research direction in the future. According to the physicochemical characteristics of oily sludge and the ideas of "combined harmless disposal with recycling", the application of the harmless disposal and recycling of the oily sludge will be realized.