Abstract: By taking the engineering geology of the Fe-Zn polymetallic ore in Chaobuleng mine as an example, based on the blast damage theory of rock, the FLAC-3D software was adopted and ultrasonic tests were carried out to systematically explore the cumulative damage development in the surrounding rock of the re-exploited tunnel. In the above investigation, the surrounding rock was impacted by blasting for many times in the section excavation process. And the re-exploitation of the tiberium spike under the mined-out area adjacent to the re-exploited tunnel was numerically simulated. Thereby the stability of the surrounding rock of the mined-out area was analyzed. It is helpful for engineering application.