An anti-reversing device (3) of a trocar (100), and trocar (100); the anti-reversing device (3) comprises a lock catch (31) capable of preventing a reversing movement of an end sealing member (1), and a slack switch (32) capable of releasing a prevention of the reversing movement of the end sealing member (1) by the lock catch (31); and the slack switch (32) is pressed down, such that a restriction by the lock catch (31) on the reversing movement of the end sealing member (1) can be released. When the end sealing member (1) is detachably installed at a near end of a sleeve (2) via a rotation method, the lock catch (31) prevents the reversing movement which causes the end sealing member (1) to fall off, thus preventing air leakage or preventing the end sealing member (1) from falling off from the near end of the sleeve (2); and when the slack switch (32) is pressed down, the restriction by the lock catch (31) on the reversing movement of the end sealing member (1) can be released, and the end sealing member (1) can be detached from the near end of the sleeve (2) via the reversing movement. The trocar (100) comprises the anti-reversing device (3), thus improving the reliability of the trocar (100).La présente invention concerne un dispositif anti-inversion (3) d'un trocart (100) et un trocart (100) ; le dispositif anti-inversion (3) comprend un loquet de verrouillage (31) capable d'empêcher un mouvement d'inversion d'un élément de scellement d'extrémité (1), et un commutateur de détente (32) capable de libérer une prévention de l'inversion de mouvement de l'élément de scellement d'extrémité (1) par le loquet de verrouillage (31) ; et le commutateur de détente (32) est pressé vers le bas, de sorte qu'une restriction par le loquet de verrouillage (31) du mouvement d'inversion de l'élément de scellement d'extrémité (1) puisse être libérée. Lorsque l'élément de scellement d'extrémité (1) est installé de façon détachable à une extrémité proche d'un manchon (2) par l'interm