A grooved universal radial seal ring used in a trocar and a trocar are provided. The radial seal ring includes one or more easily-deformable grooves, one or more supporting areas capable of guiding surgical device movement, and a through hole, the supporting areas of the seal ring are connected by the easily-deformable grooves, a thickness of the easily-deformable grooves is much smaller than an average thickness of the supporting areas, so that when a surgical device is inserted along a cone-shaped guiding groove of the supporting areas, the easily-deformable grooves deform first and surround the surgical device because a wall thickness of the easily-deformable grooves is very small, thereby achieving a sealing effect. When the surgical device shakes, the supporting areas separated by the easily-deformable grooves also shake together, but the seal ring formed by the easily-deformable grooves still surrounds the surgical device, thereby always keeping a sealed state and achieving an excellent dynamic sealing effect. Particularly, the thickness of the easily-deformable grooves is small, not only a dynamic sealing effect is excellent, but also surgical device moving resistance is small. The trocar realizes any replacement among surgical devices with diameters being 12 millimeters (mm), 10 mm, and 5 mm, thereby bringing convenience to surgical operation.
