Filling system for air rail system

The filling system comprises a first bin body, a second bin body and a discharging part, a freight transport unit is arranged on a track beam to move to conduct transfer operation, coal mine materials are arranged in a first containing space in the first bin body in advance, and under the filling rhythm, the first containing space is filled with the coal mine materials, and the second containing space is filled with the coal mine materials. The coal mine materials enter the second containing space of the second bin body through the first discharging opening, after the freight unit moves to the lower portion of the discharging part, the coal mine materials enter the freight unit through the discharging part, the freight unit does not need to be operated to be repeatedly disassembled from the track beam in the whole process, and therefore the operation efficiency is improved, and the labor intensity of workers is reduced. And through telescopic operation of one end of the discharging part, the filling uniformit