<p>Flexible strain sensors demonstrate significant potential for applications in wearable devices, biomedical monitoring, and intelligent robotics. However, their practical implementation is often hindered by insufficient stability and sensitivity under extreme environmental conditions, such as moisture and corrosive media. This review focuses on resistive-type superhydrophobic carbon nanotube (CNT)-based flexible strain sensors (SCFSS), systematically summarizes recent advances in their design strategies, performance optimization approaches, and application advancements. From a materials fabrication perspective, key technologies for enhancing both sensing performance and superhydrophobicity are discussed, including silane surface modification, polymer/nanoparticle composite coatings, and micro-nano bio-inspired hierarchical structure design. Concurrently, the synergistic enhancement mechanisms of advanced processing techniques—such as solution processing, electrospinning, and biomimetic manufacturing—on these properties are elucidated. At the application level, the groundbreaking progress of SCFSSs in wearable devices (e.g., human motion monitoring, water rescue), industrial inspection (e.g., gas leakage warning), and environmental monitoring is detailed. By incorporating superhydrophobic interfaces, these sensors effectively address the pervasive issue of signal drift commonly encountered by conventional sensors in humid or corrosive environments. To address remaining challenges related to long-term mechanical durability, scalable green manufacturing, and multifunctional integration, this review prospectively proposes corresponding solutions. These include the integration self-healing materials, the development of roll-to-roll continuous manufacturing processes, and the application of multi-modal signal decoupling algorithms. These strategies provide crucial theoretical guidance and technical pathways for the practical utilization of SCFSSs in extreme environments.</p> Graphical Abstract <p></p>