The invention belongs to the field of titanium tetrachloride refining and in particular relates to a method of refining titanium tetrachloride to remove vanadium by employing drainage oil. In order to solve the problems that an existing remove-removal reagent for titanium tetrachloride is high in cost and the like as the drainage oil is great in output and low in cost and is not efficiently utilized, the invention provides the method of refining titanium tetrachloride to remove vanadium by employing drainage oil. The method comprises the following steps of: stirring and mixing the drainage oil and oleic acid in a pre-heating kettle; preheating the mixture to 136-140 DEG C; adding the preheated mixture into a remove-removal rectifying tower; introducing coarse titanium tetrachloride gas; and collecting the refined titanium tetrachloride without vanadium in a remove-removal rectifying tower condenser. By reasonably matching the drainage oil and the oleic acid, the method of refining titanium tetrachloride to remove vanadium not only provides a novel utilization path for cheap drainage oil, but also saves the cost of refining titanium tetrachloride to remove vanadium. The method provided by the invention is simple to operate and low in cost and has an important economical benefit.