Mechanical fiber sensors that can be seamlessly integrated into traditional fabrics have significant potential for imperceptible sleep monitoring. Wet-spinning techniques are an effective method for fabricating fiber sensors. However, the sensors produced by this process have a single, homogeneous linear structure, which limits their high sensitivity and linearity to low-pressure ranges and presents challenges for stability. To address this issue, we propose an improved wet-spinning process for the large-scale production of a capacitive sensor that features both multilevel structure of varying heights and a core-sheath configuration (with commercial conductive yarn as the core and TPU as the sheath).Thanks to its multilevel structure, a multilevel structure fabric pressure sensing belt (MSFPSB) woven from this fiber sensor exhibits excellent linearity (R2 = 0.998) and sensitivity (0.077 kPa⁻1) over a pressure range of 3.3–30 kPa. Furthermore, the commercial conductive core ensures the sensor's stability after 4000 compression cycles. Additionally, we have developed a battery-free, wireless, stick-on-and-use-immediately data acquisition tag based on near-field communication (NFC). The tag works with a reader placed 5 cm away to imperceptibly monitor breathing, ballistocardiogram (BCG), and body motion signals during both work and sleep. This approach enhances the comfort of sleep monitoring and helps detect potential sleep disorders.