The invention discloses a trocar seal membrane with multi-dimensional floating pleats. Said seal membrane comprises a proximal opening, a distal aperture, an outer seal body extending from the proximal opening to the distal aperture, and an inner seal body extending from the distal aperture to the proximal opening. Said outer seal body and said inner seal body extend to be intersected and form a flange； said distal aperture formed by a sealing lip for accommodating the inserted instrument and forming a gas-tight seal； said outer seal body includes at least one radial pleat； each radial pleat includes at least two annular-pleat-walls and at least one of the annular-pleat-walls include a plurality of tangential pleats. In the invention, under the essentially equivalent condition of geometric size, the deformation force of said multi-dimensional pleats is much smaller than the deformation force of said two-dimensional pleats
