Abstract: Based on the requirements of flexible electronic devices on flexible substrates, the substrate should be thin enough and achieved sufficient toughness. Two-dimensional materials show extremely strong development potential due to atomic thickness. So far, graphene, silene, phosphorene and two-dimensional transition metal chalcogenide compounds are typical representatives of two-dimensional materials. Their structure, characteristics and preparation methods affect their application in flexible electronic devices. In this review, the above mentioned two-dimensional semiconductor materials are employed as elaboration goals, and their application statuses in flexible organic light-emitting diodes, organic thin-film transistors and field-effect transistors are reviewed based on their synthesis, modification and two-dimensional nanostructures controlling. The problems that need to be solved urgently in the future are described in detail also.