<p>With the rapid development of hydrogen energy technology, ensuring the safety and high efficiency of its application necessitates real-time and accurate monitoring of hydrogen concentration, which imposes higher requirements for high-performance hydrogen sensors. However, current hydrogen sensors are often constrained by factors such as size, detection range, sensitivity, and mass production capability, making it difficult to achieve large-scale and distributed monitoring applications within hydrogen energy systems. This study develops a micro-electromechanical systems (MEMS) hydrogen sensor operating on the thermal conductivity sensing principle, utilizing complementary metal oxide semiconductor (CMOS) technology to integrate a heating unit and a thermal sensing unit. By arranging the microheater and a double-layer stacked thermocouple in an equidistant diagonal arrangement and vertical distribution design, and combining it with a back cavity release to form a closed membrane-type structure, the device achieves precise control over temperature and its gradient, as well as efficient thermoelectric conversion. Results show that the device maintains low power consumption and rapid response while achieving a sensitivity of 27.06 mV/%, with a limit of detection (LOD) as low as 20 ppm for hydrogen, demonstrating significant advantages in hydrogen concentration detection. Furthermore, through cross-calculation data from multiple sensors for gas mixture, we successfully resolved the concentration information of H₂ in a gas mixture containing N₂, CO₂, CH₄, and H₂, with an error margin within 5%. This work provides an integrated novel gas monitoring method for smart energy networks, with broad application prospects in distributed hydrogen monitoring networks such as hydrogen fuel vehicles, green hydrogen plants, and power generation systems.</p>