Abstract: As a typical kind of soft rock, schist has obvious anisotropic characteristics, which easily leads to local bias load for the tunnel passing through schist rock mass, seriously threatening to the safety of the tunnel lining structure. Schist is widely distributed along Guzhu expressway, and a number of tunnels appeared secondary lining crack problem in different degrees. The schist anisotropy and the cracking law and mechanism under anisotropic effect were analyzed through site monitoring and numerical calculation. The research shows : ①Schist has obvious anisotropic characteristics, which easily generates bias load to lining structure. The load on lining in bias region is larger than that in other regions;②Secondary lining structure in bias region is the first to crack and the fracture distribution is more serious than other regions. The study reveals the crack characteristics and mechanism of secondary lining structure under anisotropic effect, which provides reference basis for ensuring construction and operation safety of schist tunnel of Guzhu highway and other similar projects.