Flexible sensors are an important component of wearable medical electronics and hold considerable promise for research. Presently, stretchable strain sensors face two primary challenges: balancing the sensing range with sensitivity, and ensuring compatibility between conductivity and mechanical properties. Here, flexible sensing fibers with high gauge factor (GF) and wide monitoring range are reported based on a hierarchical structure composed of electrostatic adsorption principle and hydrogen bonding interactions. The hierarchical structure material consists of thermoplastic polyurethane (TPU), MXene, polypyrrole (PPy) and waterborne polyurethane (WPU). Among them, MXene (2D) and PPy (3D) are uniformly distributed on the surface of the MXene/TPU fiber (1D) to form a conductive and sensing pathway. This multi-dimensional combination approach enables the fiber sensor to have a high sensing range (0 ∼ 106 %) and high sensitivity (60 ∼ 3.23 × 106). In addition, the WPU acts as a protective layer, which not only reduces the damage to the sensing layer, but also improves the stretchability (>750 %) and modulus (∼12 MPa) of the sensor. Therefore, it can function as fiber sensor for monitoring not only human movement but also swelling in the legs of patients with varicose veins. The sensor also has a joule heating effect, as well as the potential to be integrated into fabrics, providing an important case for the construction of multifunctional flexible wearable medical electronics with practical applications.