As one of flexible electronic devices, flexible pressure sensors have many merits such as high sensitivity, excellent flexibility and facile fabrication process, and they have been widely used in many burgeoning fields including wearable devices, health care, soft robots, human-machine interaction, etc. Sensitivity, detection limit, response time and cyclic stability are the key parameters of the flexible pressure sensors, and the introduction of micro/nano- structures into flexible pressure sensors will play an important role in improving their comprehensive performance. Based on the main types of micro-nano structure, this review introduces the latest research progress of flexible pressure sensors, including the influence of various morphological micro-nano structures on the performance of flexible pressure sensors and their applications in flexible electronics. Moreover, the prospect of their future development is also outlined.