Abstract: The problem of highway tunnel defects has become an unavoidable factor that affects traffic safety. Taking a water-rich soft rock expressway tunnel as the research object, and in combination with the tunnel hydrogeological conditions and the tunnel defect conditions, the causes of inverted arch defects are analyzed, the simulation analysis is carried out by a numerical calculation software, and then the complete treatment measures are proposed accordingly. Actual results show that the treatment measures are reasonable and effective. On this basis, a set of treatment schemes is summarized for defects in the tunnel inverted arch in weak surrounding rock with rich groundwater,so as to provide references for treating the defects of the inverted arch under similar conditions and to put forward some suggestions for tunnel design under similar conditions.