Disclosed are a low-resistance general sealing apparatus for a trocar and a trocar. A sealing ring (3) is compressed between an upper guiding mechanism (1) and a lower guiding mechanism (2). A smooth transition between the upper guiding mechanism (1) and the lower guiding mechanism (2) minimizes the contact area between the sealing ring (3) and a surgical instrument, which not only provides a guiding function when different forms of surgical instrument are inserted or removed, but also maximally transforms a "soft-hard" friction area between the sealing ring (3) and the surgical instrument into a "hard-hard" friction area between the plastics of upper and lower guiding mechanisms and an outer metal sheath of the surgical instrument, thereby greatly reducing the motion resistance, and meanwhile, having an excellent sealing effect. The sealing apparatus and the trocar are also applicable to instruments with diameters between 5 mm and 12 mm.
