A laryngeal mask airway device includes a flexible tube set and an annular mask. The flexible tube set has an airway tube and an air guide tube that are juxtaposed. The annular mask has an outer membrane surrounding an outer periphery of one end of the airway tube and an elastic filler disposed inside the outer membrane. The outer membrane is in communication with one end of the air guide tube. When in use, the outer membrane is first squeezed to compress the elastic filler, and then the other end of the air guide tube is closed. The inside of the outer membrane forms a negative pressure to maintain the elastic filler in a small volume, so that one end having the annular mask of the flexible tube set can be placed and positioned in a patient's throat.
