Sputum aspirator with oral cavity expansion function

According to the technical scheme, the sputum aspirator with the oral cavity expansion function is characterized in that when an oral cavity is expanded, a guide ring is pulled upwards to drive a connecting piece and a limiting sleeve to move upwards, so that an expansion rod loses limitation of the limiting sleeve and a silica gel cover, a first spring rebounds outwards after losing pressure, and therefore the expansion rod is expanded; the expanding angle of the expanding rod can be adjusted by adjusting the position of the limiting sleeve when the limiting sleeve and the silica gel cover move upwards, and the expanding angle of the expanding rod can be adjusted, so that the problems that when sputum suction is carried out on a patient, the patient may unconsciously close the oral cavity, and consequently the expansion of sputum suction work may be hindered are solved; the oral cavity of the patient is difficult to expand, so that the sputum suction difficulty is possibly increased, and the sputum suction e