Locking device for tunnel segment

The invention discloses a locking device for a tunnel segment. The locking device for the tunnel segment comprises a first baffle, a second baffle, a first lead screw, a first locking component, a second locking component and a third locking component, wherein the first baffle is fixed on a front-end bottom plate; the second baffle is fixed on a first rear-end bottom plate; the first lead screw penetrates in the first baffle and the second baffle; the first lead screw is fixed on the first baffle by the first locking component, and is fixed on the second baffle by the second locking component; the front-end bottom plate is fixed on a K-shaped segment of a tunnel segment; and the first rear-end bottom plate is fixed on an A-shaped segment by the third locking component. By the locking device for the tunnel segment, the retreating amount of the K-shaped segment retreating towards a tunneling direction in a construction process can be reduced, the probability of water leaking from gaps due to the fact that gaps among segments are over large is reduced, and assembling quality of shield segments is improved.