The invention discloses a method of reducing harmful factors in the process of corn oil refining, and relates to the technical field of oil processing and refining. The method is completed with the following steps: primary alkali refining, secondary alkali refining, decolorization, dewaxing, double-tower double-temperature deodorization process. The method has the advantages that the technology is advanced and novel, multiple alkali refining and double-tower double- temperature deodorization process can ensure the quality of the intermediate process products in a control state, more importantly, toxicity of the corn grade oil factor content is reduced greatly, so that the clean and healthy corn oil can be achieved with comprehensive nutrition.