This text applies grey target theory to evaluate the safety of highway alignment design. According to grey target theory, many factors which affect the safety were selected. The model of the safety evaluation of highway alignment design model was put forward based on grey target theory. After we apply this method in the practice, this method of the safety evaluation of highway alignment design is proved to be effective in course of the accuracy of the safety evaluation. Investigative results indicate that some subjective factors can be eliminated to a certain extent based on evaluation model of grey target theory in the course of alignment scheme choice，which make the choice result more objective. And it is a certain application value for the safety evaluation of highway alignment design.