Moiré superlattices formed by van der Waals materials with small lattice mismatch or twist angle open an unprecedented approach to generate flat bands that don’t exist in the “parent” materials, which provides a controllable platform for exploring quantum many body physics. Owing to the wide angle range for the existence of flat bands, as well as the valley-spin-locking band structure and the excellent optical properties, twisted semiconducting transition metal dichalcogenides (TMDs) heterostructures have recently attracted lots of attention. In this review, we discuss the exotic states discovered in the twisted TMDs heterostructures, including Mott insulator, generalized Wigner crystals, topological non-trivial states, and moiré excitons, how to manipulate these exotic states and related mechanisms, and finally some perspectives on the opportunities and challenges in this field.