Pneumatic fast plug convenient to mount

The utility model discloses a pneumatic fast plug convenient to mount. The pneumatic fast plug comprises a plug body, a sealing ring, and a locking component avoiding the fall-off of an externally-connected air tube. A mounting hole for the insertion of the externally-connected air tube is arranged at one end of the plug body, and a breather hole communicated with the mounting hole is formed at the other end of the plug body; the sealing ring and the locking component are arranged in the mounting hole; the locking component comprises a locking piece, an internal limiting piece, an external limiting piece, and a pressure cap, wherein, the locking piece is clamped on the externally-connected air tube, the internal limiting piece and the external limiting piece are used for limiting the locking piece, and the pressure cap is used for preventing the externally-connected air tube from slipping off the locking piece; and a fastening part is arranged in the breather hole of the plug body. In addition, the fastening