In order to solve the safety problem of different grades roads and crashworthy capacity of overpass design, to meet the traffic safety requirements under different conditions, by using similar principle, several overpass crashworthy barrier in different levels had been gotten here, and had been proved to have better adaptability. In preliminary work, the optimum structure parameter of SH overpass crashworthy barrier had been gotten through orthogonal test, and this research is also based on the orthogonal test majorization result. During the similarity design, the similarity design for every parameter of barrier would be done through measuring the impact force, and to get the optimum structure parameters of overpass crashworthy barriers in different degrades. Finally, every group similarity majorization result had been checked, and the result showed that different grades crashworthy barrier which based on similarity principle design could meet the safety requirements for different crashworthy grades overpasses. This design not only could reduce cost, but also had better suitability and engineering utility.