A pneumatic packaging apparatus includes a fixed base provided thereon with a pressure cylinder unit connected with a chuck unit. The fixed base is further mounted with a valve seat combined thereon with a driving unit and a control unit. The control unit is able to receive external high pressure gas and control the high pressure gas to flow to the driving unit and to the pressure cylinder unit to let the driving unit and the pressure cylinder unit driven by air pressure to automatically pull tight the packaging strap and firmly squeeze the packaging fastener for fixing the packaging strap in place. Thus, the pneumatic packaging apparatus of this invention can assist users to complete packaging work with quickness, able to elevate efficiency of the packaging work.