Variation　of　driver　workload　degree　on　freeway　was　analyzed　in　order　to　research　safe　and　comfort　of　alignment　and　provide　a　new　technical　support　for　humanization　road　design.　A　total　of　12　healthy　adult　drivers＇　heart　rate　variability　index　and　operating　speed　are　tested　on　77　sections　of　one　mountainous　freeway.　According　to　the　change　law　of　different　drivers＇　workload　degree　on　different　alignment　conditions,　4　sections　can＇t　meet　the　expectations　of　the　truck　drivers＇　safe　and　comfort.　In　addition,　accident　data　is　used　to　verify　the　dangerous　sections.　Research　results　can　be　applied　to　design　road　alignment　that　meets　the　driving　expectations　of　different　drivers.