With highway traffic of China developing faster and faster, safety problems are gradually becoming more and more obvious. Such problems are big threat to both peoplepsilas lives and their property. Some safety researches have been done by Predecessors. Based on these researches, this article is to employ a highway safety evaluation system made of running velocity. By using the BP neural network algorithm in MATLAB software, simulations were made to evaluate the linearity of a certain highway. And the results come out at last to prove that the method contains a certain applicable value.