Single-hole trocar

The invention discloses a single hole trocar, which comprises a cannula (1), wherein the cannula (1) consists of an outer tube (2) and an inner tube (3), an endoscope tube (6) is axially arranged in the inner tube (3), a position limiting clamp groove structure is arranged between the outer tube (2) and the inner tube (3), and comprises clamp heads (4) and clamp grooves (5), the clamp heads (4) are arranged on the outer circle surface of the inner tube (3) in an annular array way, and the clamp grooves (5) are in clearance clamping connection fit with the clamp heads (4) and are formed in the inner wall of the outer tube in an annular array way. The single hole trocar has the advantages that the structure is simple, the endoscope body position fixation can be conveniently realized, the labor is saved by an endoscope holder, and great space is reserved for other instruments, so that the surgery operation is convenient.