Abstract: Aiming at the increasing cracking of secondary lining of the road tunnel with long time operation, the cal? culation method of discrete element-finite difference coupling is adopted to study the cracking process of secondary lining under the effect of rheological load, and the effect of geo-stress and voids behind the lining on the characteristics of secondary lining cracking is discussed. The results show that: (1) geo-stress has significant effect on the cracking patterns of tunnel lining, cracks mainly occur near the crown and invert when λ=0.5, while cracks congregate near the left and right arch haunches when λ=1 or 2; (2) the cracking processes and final failure patterns of tunnel lining in condition of voids at crown are different from that with no void, however the situation is similar to that with no void if there are voids at spandrel; the situation of cracking process is different from that with no void but the final failure pattern is similar to that with no void if there are voids at haunch; (3) if there are voids at crown and spandrel, the cracking process and final failure pattern of tunnel lining are similar to that only with voids at crown; if there are voids at spandrel and haunch or at crown and haunch, the cracking process and final failure pattern of tunnel lining are different from that with single void; (4) cracking of concrete occurs near the voids in conditions of different voids numbers and combinations.