In air transportation， children aged 2 and above can use aviation seat belts for restraint； however， these seat belts are designed for adult passengers， and their protective effects on children aged 2 and above still need to be studied. This study focuses on three types of restraint systems-aviation seat belts， Child Aviation Restraint System and child seats， and evaluates the protective effects of different types of restraint systems on children and their impact on rear passengers through sled tests. The results show that the protective effect of aviation seat belts is poor， and the head of the child dummy will hit the back of the front seat backrest， posing risks of injury to the neck and chest. When used in conjunction with aviation safety belts， CARES demonstrates higher compatibility with aviation seats， with lower injury data for the head， neck， chest， and abdomen compared to injury criteria. Despite better protection for children provided by the forward facing child seat than aviation seat belts and CARES， there are installation difficulties and other issues. Larger pre-tensioning force of the safety belt that secures the child seat produces better protective effect on children， and the rear passengers have little influence on the protection effect of the front child seat. However， using child seats can strengthen the stiffness of the aviation seat back， thus increasing the risk of head injuries for rear passengers， though with a relatively small impact on neck injury. Meanwhile， the impact of using child seats on head injuries of rear passengers is related to the distance between the seats.