Interfacial capacitance sensing technology shows great potential in the fields of flexible electronics and healthcare. However, further advancements are necessary to enhance the sensitivity and mechanical stability of all-fiber iontronic tactile sensors (ITSs), especially under high pressure. This study addresses these challenges by optimizing the electrode structure and composition, incorporating hydrophilic cotton fibers as the dielectric layer framework. As a result, the ITSs exhibit ultrahigh sensitivity (58853 kPa), rapid response times (below 2 ms), and improved mechanical stability, enduring 10,000 cycles at 195.2 kPa. Moreover, these sensors have proven effective in detecting human motion and physiological signals in both air and aquatic environments. Integration into a motion state recognition system demonstrates potential applications in sports injury recovery, stroke rehabilitation, and chronic pain management.