The invention discloses a trocar seal membrane with reverse Concave-channels. Said seal membrane comprises a proximal opening proximal opening, a distal aperture, and a sealing wall extending from the distal aperture to the proximal opening, said distal aperture formed by a sealing lip for accommodating the inserted instrument and forming a seal housing； said sealing lip comprises a longitudinal axis and a transverse plane substantially perpendicular to said longitudinal axis. Said sealing wall in the lip-adjacent area comprises the main rotary-wall and a plurality of reverse Concave-channels, which are recessed from the distal surface of the main rotary-wall toward the proximal surface and the reverse Concave-channel opening pointing to the direction of the distal surface. The shape of the reverse Concave-channel from the perspective of proximal surface is represented as a hollow convex-rib that is raised from the proximal surface. Said reverse Concave-channel has the functions of enlarging hoop circumference, reducing the wrapped area, improving lubrication reliability, increasing the axial tensile stiffness, thereby greatly reducing said frictional resistance and the stick-slip.
