Puncturing card with adjustable caliber

The utility model discloses a trocar with an adjustable caliber, and relates to the technical field of medical instruments. The second sleeve is arranged below the first sleeve, the caliber of the second sleeve is adjustable, the supporting mechanism is arranged in the second sleeve and enables the caliber of the second sleeve to be changed, and the supporting mechanism comprises a first supporting piece and a second supporting piece connected to the lower portion of the first supporting piece in parallel; the first supporting piece and the second supporting piece are the same in structure and each comprise a supporting ring provided with at least one notch and an adjusting mechanism arranged in the notch. The initial state of the trocar is small-caliber, and after the trocar is inserted into a puncture opening, the rotating shaft can be rotated according to the size of the puncture opening, so that the caliber of the trocar with the adjustable caliber is expanded to open the puncture opening. 本实用新型公开了一种口径可调的