The utility model discloses a negative ring duct piece connecting device for shield tunnel construction, which comprises a plurality of support frame bodies uniformly distributed between two adjacentnegative ring duct pieces, each support frame body comprises an upper support plate and a lower support plate which are horizontally arranged at intervals, and a web plate is longitudinally arranged between the upper support plate and the lower support plate; connecting plates are longitudinally and fixedly arranged at the two ends of the upper supporting plate and the two ends of the lower supporting plate respectively, and arc-shaped bolts connected with the duct pieces on the two sides are arranged in through holes formed in the connecting plates in a penetrating mode. The negative-ring duct piece cutting device is simple in structure, easy to manufacture and convenient to install and use, due to the fact that the supporting frame body is additionally arranged between the two negative-ring duct pieces and is not squeezed together any more, large thrust can be evenly transmitted, the supporting frame body is cut in the dismounting process, and after extrusion force between the negative rings is completely unloaded, the negative-ring duct pieces are hoisted out in a blocked mode through a crane. And the multiple pieces of supporting profile steel behind the reaction frame do not need to be cut off, construction is more convenient, the dismounting efficiency is greatly improved, and damage to the duct pieces is reduced.