High-performance humidity sensors have received widespread attention for their wide use in healthcare, archaeology, electronic device manufacturing, etc., thus developing humidity sensors with wide sensing range, high response, narrow humidity hysteresis, fast response/recovery, and excellent stability are urgently needed. Humidity-sensitive materials are the core 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 was prepared through in-situ polymerization, and the corresponding humidity sensor was fabricated via drop-casting. The structure, functional groups, specific surface area, and element distribution of the CMP material were 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 lead to tight dependence of the proton conductivity and impedance of the sensing material on the humidity. The results show that the optimized CMP sensor is highly sensitive to humidity change with high response of 516.7 at 43% RH and 1.24×10⁵ at 85% RH, narrow hysteresis of 1.9% RH, and short response/recovery time of 2.8 s and 1.2 s in the humidity range of 7–85% RH. Compared to reported MOFs-based humidity sensors, the CMP sensor exhibits unique technical characteristics. Further, the humidity sensing mechanism of the CMP sensor was investigated through a combination of material characterization, water adsorption kinetics, carrier concentration, complex impedance spectroscopy (CIS) plot, and equivalent circuit (EC). As proof of concept, by monitoring the humidity on the finger surface, we evaluated the potential applications of the CMP sensor in noncontact sensing. Moreover, a palmar hyperhidrosis diagnosis system based on the CMP sensor was assembled, realizing quick, intuitive, and accurate diagnosis the severity of palmar hyperhidrosis. It is believed that this work provides a reasonable strategy for constructing high-performance humidity sensors.