Process for preparing naphthalene by rectification

The invention refers to a kind of chemical technology, especially a kind of method of producing naphthalene by rectification, and chooses the still residue left by the rectification of carbon-10 heavy aromatics as the raw material. The invention chooses the still residue left by the rectification of carbon-10 heavy aromatics, which once was forgotten by people, as the raw material of the technology of producing naphthalene by rectification and reuses the flotsam. The sulphur content of the still residue is less than 5ppm and there is no need to desulfurize, which reduces the production cost. The finally produced naphthalene content is as high as over 83%.