High-performance humidity sensors have received widespread attention due to their numerous applications in fields, such as healthcare, archaeology, and electronic device manufacturing. Therefor there is an urgent need to develop humidity sensors with a wide sensing range, high response, narrow humidity hysteresis, fast response/recovery, and excellent stability. Humidity-sensitive materials are the core components of humidity sensors. To obtain high-performance humidity sensors, humidity-sensitive materials should have high hydrophilicity, conductivity, and stability. Metal organic frameworks (MOFs) are promising humidity-sensitive materials due to their special characteristics, but often limited by the poor conductivity and hydrophilicity. Herein, a proton conduction enhanced CMC-Na/MOF-801/PPY (CMP) humidity-sensitive material is prepared through in-situ polymerization, and the corresponding humidity sensor is fabricated through drop-casting. The structure, functional groups, specific surface area, and element distribution of the CMP material are investigated by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), N₂ sorption isotherm, transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). The abundant hydrophilic groups and continuous hydrogen bond network results in a strong dependence of the proton conductivity and impedance of the sensing material on humidity. The results show that the optimized CMP sensor is highly sensitive to humidity change, with response values of 516.7 at 43% RH and 1.24×10⁵ at 85% RH, It also features a narrow hysteresis of 1.9% RH and short response and recovery times of 2.8 s and 1.2 s, respectively within a humidity range of 7% RH-85% RH. Compared with the MOFs-based humidity sensors reported previously, the CMP sensor exhibits unique technical characteristics. Furthermore, the humidity sensing mechanism of the CMP sensor is studied using a combination of material characterization, water adsorption kinetics, carrier concentration analysis, complex impedance spectroscopy (CIS) plot, and equivalent circuit (EC). As proof of concept, we evaluate the potential applications of the CMP sensor in noncontact sensing by monitoring the humidity on the finger surface. Moreover, a palmar hyperhidrosis diagnosis system based on the CMP sensor is assembled, enabling quick, intuitive, and accurate diagnosis of the severity of palmar hyperhidrosis. It is believed that this work provides a reasonable strategy for constructing high-performance humidity sensors.