Puncture device

The invention relates to a puncture device which is good in sealing performance. The puncture device comprises a sealing assembly, wherein the sealing assembly comprises a plurality of elastic sealing pieces arranged between a pair of rings. Each elastic sealing piece comprises a conical surface thin wall part in the shape of a circular cone and an annular part connected to the bottom of the conical surface thin wall part, wherein a fan-shaped notch is formed in the conical surface thin wall part, and the top end of the fan-shaped notch is the top end of the conical surface thin wall part. The annular parts of the elastic sealing pieces are stacked to enable the conical surface thin wall parts of the elastic sealing pieces to form a conical sealing piece, and then a surgical instrument penetrating through the sealing assembly is made to be in clearance fit with the sealing assembly in a sealing mode. A 300-340 degree circumference is arranged on the bottom of the conical surface thin wall part of each elastic sealing piece. After the surgical instrument penetrates through the sealing assembly, the lateral wall of the surgical instrument can be wrapped with the radial edges of the fan-shaped notches of the elastic sealing pieces more tightly, so that sealing performance is improved, and even when the air pressure in the enterocoelia reaches 8KPa, air leakage can not happen.