An apparatus and method for filling a continuous air filling type air enclosure with air comprises moving first an air cylinder film sheet onto a working platform, hot-sealing two outer films of the air cylinder film sheet using a hot sealing device to form an air filling passageway, moving an air filling head into the air filling passageway and then using a clamping apparatus to press the two outer films tightly to attach onto the air filling head to allow air in the air filling head to be filled into the air filling passageway and enter an air cylinder of the air cylinder film sheet via an air inlet of the air cylinder film sheet to cause the air cylinder to be filled with air and expanded.