Shield segment pre-reinforcing structure based on air bag steel ring and construction method

The invention discloses a shield segment pre-reinforcing structure based on an air bag steel ring. The shield segment pre-reinforcing structure based on the air bag steel ring comprises lining segments, an inner steel ring layer, a roadbed slab and a fixing mechanism, wherein the lining segments are laid and spliced along the inner part of the tunnel to form an annular outer ring part; the roadbed slab is arranged at the bottom of the inner wall surface of the annular outer ring part; the inner steel ring layer is connected with the lining segments and laid along the inner wall surface of the annular outer ring part, the inner steel ring layer comprises an air bag layer and a steel ring layer, and the air bag layer is arranged between the steel ring layer and the lining segments; the inner steel ring layer is connected with one end of the fixing mechanism, and the other end of the fixing mechanism is connected with the roadbed slab. In order to prevent the transverse deformation of the tunnel shield segments