The utility model discloses a tracheal cannula saliva blocking and collecting device. The device comprises a near-end cannula connector used for connecting a tracheal cannula, a far-end cannula connector, a hollow and conical blocking cover and a hollow balloon. The device has the advantages that when the cannula results in that a patient coughs and chokes, the ejected respiratory tract sputum and the saliva in the laryngo-pharynx can be blocked by the blocking cover and collected by the balloon and will not ejected to the body of a medical worker, and meanwhile the operation of oxygen therapy, sputum suction and the like can be performed through a bending channel of a far-end cannula or an opening in the bending channel of the far-end cannula. Thus, the tracheal cannula saliva blocking and collecting device has the advantages of being simple in structure, convenient to use and capable of well protecting the medical worker and a medical device, and reducing germ spread and nosocomial infection.