Abstract: The tail tunnel No.2 in Shisanling pumped storage station has operated for many years, it has been found that there were large numbers of circumferential and longitudinal crack in the concrete lining when empted for inspection, those cracks will affect the tunnel safety operation and concrete endurance. By means of chemical grouting methods, adopting advanced equipment and technique, repair treatments have been carried out for part severe cracks, which achieved expectant effects.