The single station level passenger transport organization shall follow the principle of "from bottom to top, from inside to outside" (the elevated station shall follow the principle of "from top to bottom, from inside to outside") and the principle of "first control the arrival, then control the transfer" to implement the three-level passenger flow control. In case of sudden large passenger flow, the station shall take passenger flow control measures according to the actual situation to achieve the effective mitigation of passenger flow. When the passenger flow control is adopted on site, the passenger flow is still out of control, so higher level passenger flow control measures can be applied to achieve the situation of "orderly and controllable" passenger flow