Hydrogen embrittlement usually manifests as delayed fracture under stress. The phenomenon of delayed fracture occurs because the hydrogen in the part diffuses to the stress concentration part and gathers the metal defects in the stress concentration part (atomic lattice dislocation, holes, etc.). Hydrogen diffuses into these defects, and hydrogen atoms change into hydrogen molecules to generate enormous pressure. This pressure and the residual stress inside the material and the external stress of the material form a resultant force. When this resultant force exceeds the yield strength of the material, fracture occurs. Since hydrogen embrittlement is related to the diffusion of hydrogen atoms. Diffusion takes time, and the speed of diffusion is related to concentration gradient, temperature and material type. A pressure transmitter is a device that converts pressure signals into electrical signals for control and remote transmission. Its core components are single crystal silicon resonant sensors and measuring capsules. In order to reduce the pressure loss in the transmission process and prevent corrosion by the measurement medium. Generally, the metal thin-walled material with certain elasticity and anti-corrosion performance (the thickness is between 40 ~ 80um, which is slightly different for each equipment supplier) is selected to make the measuring diaphragm. Common measuring diaphragm materials include 316L stainless steel, Hastelloy, tantalum, titanium and many other types. Since the thickness of the measuring diaphragm is less than 0.1mm, conventional pressure transmitters are prone to hydrogen embrittlement and are affected under harsh working conditions (high temperature and high pressure and high concentration of hydrogen). As a result, the toughness of the measuring diaphragm degrades and loses its elasticity, and cavity bulges or cracks appear. Over time the hydrogen molecules can even penetrate the measuring diaphragm into the insulating silicone fluid. The presence of air bubbles increases losses during pressure transmission. It will also directly interfere with the measurement effect of the pressure transmitter, resulting in zero drift of the pressure transmitter and unstable output. Measurement errors and fluctuations in pressure measurement parameters occur. In more serious cases, the pressure transmitter may even be damaged, resulting in a safety accident. Therefore, the selection of the measuring diaphragm of the pressure transmitter under the working condition of the coal gasification device is more important.