Abstract: Ultra-thin flexible pressure sensors possess advantages such as being lightweight, highly flexible, and highly sensitive, enabling them to conform closely to the surface of human skin and achieve high-fidelity, imperceptible detection of external pressure, demonstrating broad application prospects in the field of wearable devices. However, existing devices often struggle to simultaneously achieve both high sensitivity and a wide detection range. This article reviews the working mechanisms and latest advancements of four main types of sensors: piezoresistive, capacitive, piezoelectric, and triboelectric. It also summarizes the sensor substrate and functional material systems. Key strategies for enhancing sensing performance through microstructure design are highlighted. Finally, the article reviews application progress in areas such as health monitoring, motion capture, human-computer interaction, and electronic skin, and analyzes current challenges as well as future development directions.