The retu airway tunnel of bank 6 is an important tunnel for air retu and auxiliary transportation. While under construction, the tunnel was seriously deformed, and the bottom was heavily squeezed. When completed, the bottom was smoothed out several times and a lot of maintenance were done. But about half year later, the tunnel collapsed. To counter the problems mentioned above, we systematically expounded our ideas and designed for solving the problem of the sustenance of the retu airway tunnel of section 6.