Shield launching negative ring

The utility model discloses a shield launching negative ring, which is used for forward propulsion of shield tunneling when a shield tunneling machine launches, the shield launching negative ring comprises a plurality of shield launching negative rings which are sequentially arranged along a first direction, each shield launching negative ring comprises a plurality of duct piece bodies and a buffer component, each duct piece body is of an annular structure with a local opening, the pipe piece comprises a plurality of pipe piece bodies, the pipe piece bodies are coaxially arranged, openings of the pipe piece bodies face the same direction, each pipe piece body comprises a front steel plate, a supporting steel plate and a rear steel plate which are sequentially arranged in the first direction, and a first mounting hole is formed in the end face, away from the supporting steel plate, of each front steel plate; the first buffer structure penetrates through the first mounting hole to be movably mounted on the supp