Here, we present a composite material in the form of Ti3C2Tx MXene/nylon 6 (MPA6) core-shell fibers. These fibers were synthesized through a process involving the systematic stacking of Ti3C2Tx MXene nanosheets to form a continuous film via interfacial self-assembly, followed by coating onto the surface of nylon 6 fibers. Notably, despite a minimal MXene coating of just 1.53 wt%, the MPA6 fibers exhibit remarkable electrical conductivity, reaching 11.39 ± 2.51 S/cm. The interwoven conductive network within the fabric's fibers contributes to its exceptional properties, including rapid response time (with a response time of 63 ms during pressing behavior), fatigue resistance (maintaining a stable response over 300 cycles), and consistent reproducibility of response during repeated cycles. With its increased sensitivity to various human activities, this composite fiber is well-suited for use as a wearable personal activity monitor. Additionally, its exceptional sensitivity to gravitational objects makes it a valuable tool for gravity detection, capable of detecting changes as small as 1 g.