<p>Flexible synaptic devices, as cutting-edge electronic components designed to emulate biological synaptic functions, facilitate parallel information processing and memory storage, thereby significantly enhancing the speed and efficiency of computational operations. Their inherent flexibility allows these devices to seamlessly integrate into a variety of complex environments and application scenarios, including wearable technology, smart skins, and biomedical sensors. Notably, three-terminal flexible synaptic transistors, which structurally resemble biological synapses, offer a more natural and precise emulation of diverse synaptic functionalities. In recent years, substantial progress has been made in the development of these transistors, marking a significant leap forward in neuromorphic electronics. This review comprehensively summarizes the latest advancements in flexible synaptic transistors, providing a systematic analysis of their operational mechanisms, material innovations, and applications in the field of neuromorphic perception systems. Furthermore, it offers insightful perspectives on the future opportunities and challenges that lie ahead for the continued evolution of flexible synaptic transistors.</p>