Airway management is an enormous challenge in the critical care of children. And intubation can save lives in case of emergency. In children, the airway has a significant changes and the oxygen reserve is low, so the appropriate catheter depth is particularly critical. Shallow catheter placement will lead to vocal cord injury, accidental extubation, hypoxemia and even death. Excessive placement (such as endobronchial) may result in atelectasis or traumatic lung injury. This review describes the characteristics of children's airway and the definition of catheter depth, and summarizes the characteristics of different localization methods of children's tracheal catheter positioning based on universal literature review. We also demonstrate the new methods of catheter positioning, advantages and disadvantages of these new methods, and future directions for ultrasound guided catheter placement in children.