The National Highway Traffic Safety Administration enacted the FMVSS201u in 1998. The regulation content shall be defined as the HIC(d) value of less than 1,000 in the event of a traffic accident, and shall be lower than the passenger injury AIS grade 3. In this study, the Taguchi method and CAE were performed on the upper part of the B pillar, the most vulnerable part of the FMVSS201U compliance test, to optimize space. The noise factor was used as the FMH launch speed to respond to changes in speed, while the control factor was optimized in four places where FMH directly hit. Furthermore, component stiffness was adjusted to further improve HIC(d) performance and satisfy government regulations.