In an aircraft crash, the occupants can effectively reduce impact injuries by adopting a reasonable sitting position. In order to analyze the effect of lower leg position on the injury of occupants under horizontal 16g dynamic impact, a type of triple aircraft passenger seat was taken as the research object, and a finite element model of repetitive aircraft seats/occupant restraint system was established, with a full-scale sled test carried out to verify the accuracy of the model. The results showed that the femur and neck injury of the 50th percentile Anthropomorphic Test Device (ATD) using the ‘lower leg after’ position was reduced, but the head injury was increased, under the same working conditions when compared with the ‘lower leg vertical’ position. For the 95th percentile ATD with the ‘lower leg vertical’ position, the femur injury was reduced but the neck injury was increased compared with those of the ‘lower leg forward’ position. The findings provide a reference for a relatively safer sitting position for occupants of different sizes.