Objective In order to study the effect of AEB on brain injury of pediatric occupants in buses. Method The bus AEB test scene was developed by using Prescan code. The deceleration curve under the bus AEB braking condition at initial speed of 60km/h is got by simulation method. Based on the validated finite element (FE) bus model and the mixed FE model of a 6-year-old child with detailed anatomical head structure, four typical seating positions in the bus are selected, and the head injury of child passengers seating in these positions with and without automatic emergency braking (AEB) conditions is investigated using simulation method with LS-DYNA code.The craniocerebral injury of child occupants was analyzed by using the HIC15 value of the head of child occupants, the pressure at the gray matter of the brain, the Von Mises stress and shear stress of the brain tissue as the injury evaluation indicators. Results In the simulation of each group, when the baffle is set in front of positions 1 and 2, the pressure at the gray matter of the child occupant"s brain exceeds its injury threshold, and the various injury indicators of the child occupant at other positions are far less than the corresponding injury threshold. Conclusion AEB can effectively reduce the head impact injury severity of child passengers in the bus. The pediatric passenger at position 3 in the bus are prone to higher impact head injury risk. The billboard Setting at positions 1 and 2 in the bus could increase the injury risk of child passengers.