Flexible sensors, emerging as a novel sensing technology, have progressively garnered substantial interest among researchers. In recent years, there has been a growing emphasis on the utilization of nanofiber assemblies in the advancement of flexible mechanical sensors. This approach bestows upon these sensors several merits including cost-effectiveness, streamlined processing, enhanced user experience, and superior sensing capabilities. The primary objective of this review is to comprehensively assess and summarize the utilization of nanofiber sensors within the realm of flexible mechanical sensing. This endeavor aims to furnish invaluable theoretical and practical insights for the progression of flexible sensor technologies. This paper is centered on the fabrication of nanoflexible fiber sensors, primarily by methods such as polymer direct spinning, blending, nanofiber carbonization, gas phase growth, and nano-modification. Capitalizing on advancements in nanotechnology and leveraging the inherent attributes of nanofibers, and achieving breakthroughs in the development of highly sensitive, wide-range, and rapidly responsive sensors through the ingenious design of multi-tiered sensing structures, the incorporation of high-performance conductive materials, and the construction of intricate three-dimensional conductive network have garnered increasing attention from both academia and industry. Nanofiber-based mechanosensors are electronic devices utilizing flexible nanofiber aggregates as substrates. They possess the capability to detect external mechanical stimuli and convert them into electrical signals. These sensors can be categorized primarily into resistive, capacitive, piezoelectric, and triboelectric types according to their sensing mechanisms. The enhancement of nanofiber resistive flexible sensors predominantly hinges on the optimization of the sensor matrix structure and the conductive network design. Consequently, the development of resistive sensors based on nanofibers primarily revolves around refining the micro/nanostructure on the fiber’s surface and the impact of the macro-aggregate structure on resistive sensing performance. In the area of highly sensitive nanofiber capacitive mechanical sensing, the alteration of dielectric layer morphology and the reduction of compression modulus are pivotal for achieving heightened sensitivity in capacitive flexible sensors. Consequently, research in the field predominantly focuses on dielectric layer preparation. This encompasses aspects such as surface microstructures of nanofibers, composite matrices with nanofiber porosity, and textile/nanofiber composite structures. These endeavors aim to produce capacitive sensors that exhibit both high sensitivity and a broad detection range. Furthermore, to address the existing sensitivity limitations of capacitive sensors operating on the fundamental capacitance principle, there has been a recent emphasis on the concept of introducing ionic conductors into nanofibers. This approach aims to generate bilayer capacitance at the electrolyte-electrode interface, and it has garnered significant attention. In the realm of piezoelectric sensors, researchers have predominantly explored strategies to enhance the piezoelectric performance of polymer-based nanofibers. This includes avenues such as in situ polarization, nano-doping, thermal stretching, and the application of high electric fields. Within the domain of nanofiber-based triboelectric sensors, the primary focus of research centers on the inherent friction characteristics of the materials. Complementary to this, physical and chemical techniques are employed to manipulate the nanometer-scale surface morphology and facilitate surface functionalization of the materials. This, in turn, effectively enhances parameters like contact area, contact characteristics, friction effects, and ultimately augments the performance of triboelectric effect. Flexible mechanical sensors find utility across a broad spectrum of applications, spanning but not confined to domains such as health monitoring, medical diagnostics, human motion detection, and intelligent robotics. This paper undertakes a methodical endeavor to comprehensively encapsulate the multifaceted applications of nanofiber-based flexible sensors across various domains. In the domain of sports, they can be used to monitor athletes’ posture and range, analyze athletes’ movement skills and improve their performance. In the medical field, they can be used to monitor patients’ physiological parameters, such as heart rate, body temperature, blood oxygen and water equality, to realize real-time monitoring of patients’ health status, or to make intelligent medical equipment, such as intelligent artificial limbs and intelligent rehabilitation equipment, to help patients recover their functions and improve their quality of life. In the domain of intelligent robotics, flexible mechanical sensors enable interaction and perception with the environment, elevating the intelligence level of robots and empowering them to perceive user movements and sounds. Overall, the widespread application of flexible sensors significantly enhances the quality of life for individuals in diverse fields. As a vital research direction in flexible mechanical sensing, nanofiber sensors present numerous opportunities and challenges for future development. The distinctive structure and surface properties of nanofibers underpin their exceptional sensor performance, yet their mechanism of action requires further elucidation. By thoroughly exploring the interplay between nanofibers and sensor performance, sensor design and efficacy can be better optimized. Despite their commendable performance in flexible mechanical sensing, current nanofiber sensors encounter certain practical challenges, including limited sensitivity and stability. Consequently, it is imperative to conduct further research and advancements in nanofiber preparation technology to enhance the sensor’s sensitivity and stability. In conclusion, nanofiber sensors represent a promising research trajectory in the field of flexible mechanical sensing, offering vast potential for application. By refining the preparation process, delving deeper into their mechanisms, expanding their application domains, and fostering interdisciplinary collaboration, the performance and applicability of nanofiber sensors can be further enhanced. As science and technology continue to progress, nanofiber sensors are poised to yield more breakthroughs and innovations, contributing significantly to the intelligent and health-oriented development of human society. [ABSTRACT FROM AUTHOR]