One salient feature of systems with moiré superlattice is that the Chern number of "minibands" originating from each valley of the original graphene Brillouin zone becomes a well-defined quantized number because the miniband from each valley can be isolated from the rest of the spectrum due to the moiré potential. Then a moiré system with a well-defined valley Chern number can become a nonchiral topological insulator with U(1)×Z3 symmetry and a Z classification at the free fermion level. Here we demonstrate that the strongly interacting nature of the moiré system reduces the classification of the valley Chern insulator from Z to Z3, and it is topologically equivalent to a bosonic symmetry-protected topological state made of local boson operators. We also demonstrate that even if the system becomes a superconductor when doped away from the valley Chern insulator, the valley Chern insulator still leaves a topological imprint as the localized Majorana fermion zero mode in certain geometric configuration. © 2019 American Physical Society.