Wearable devices, which are widely used, require stretchable and bendable sensors, so flexible sensors have received much attention. This paper presents a review of flexible pressure sensors in terms of microstructures, materials, and preparation processes, focusing on summarizing the different structures of flexible sensors at the present stage and comparing the important properties of flexible pressure sensors with natural microstructures, bionic surface microstructures, porous structures, multilevel structures, and multilayer structures. The commonly used flexible substrate materials and conductive active materials are introduced. Comparing the advantages and disadvantages of lithography technology, 3D printing and other manufacturing processes, it is found that the flexible pressure sensor with excellent comprehensive performance and repeatability is more complicated to manufacture and has a higher cost. The future research direction of flexible pressure sensor is prospected. This paper has a high theoretical value and engineering reference significance for related flexible devices.