Subsurface tunnel settlement monitoring system

The utility model relates to the technical field of underground excavation engineering, and discloses an underground excavation tunnel settlement monitoring system which comprises a base, the upper end of the base is symmetrically and fixedly connected with a plurality of supporting columns, the upper ends of the supporting columns are fixedly connected with the same mounting pipe, and the upper end of the mounting pipe is uniformly and fixedly communicated with a plurality of fixing pipes; a first lifting piston is movably inserted into the inner side of the fixing pipe in a sleeved mode, a lifting rod is fixedly connected to the upper end of the first lifting piston, the upper end of the lifting rod penetrates through the upper end of the fixing pipe through a first through hole formed in the upper end of the fixing pipe, and an arc-shaped jacking plate is further fixedly connected to the upper end of the lifting rod; and one side of the upper end of the mounting pipe fixedly communicates with a compensatio