Sealing structure between sheath base and dilator for ureter sheath

The utility model relates to a ureter sheath, in particular to a sealing structure between a sheath base and an expander for the ureter sheath. According to the sealing structure between the sheath base and the dilator for the ureter sheath, the sheath base is provided with a cavity allowing the dilator to stretch into, one end of the sheath base is provided with an opening enabling the cavity to be communicated with the outside, a positioning block is fixed to the end face side, provided with the opening, of the sheath base, and a sealing piece is arranged between the positioning block and the sheath base. The sealing piece comprises an annular inner portion used for making contact with the expander and an outer portion located on the outer side of the inner portion in the circumferential direction, positioning grooves and at least two positioning protrusions extending into the positioning grooves are arranged between the end face of the positioning block and the end face of the sheath base, and the number o