The article focuses on the importance of detecting hydrogen leaks in facilities like hydrogen refilling stations, particularly in the context of the increasing use of Fuel Cell Vehicles (FCVs). It discusses the limitations in assessing the performance of hydrogen sensors in confined spaces, specifically under ceilings. The study conducted by researchers from the Shanghai Fire Research Institute and the University of Shanghai for Science and Technology utilizes a catalytic combustion hydrogen sensor to monitor hydrogen leaks in confined areas. The research evaluates the impact of leak size and placement height on the distribution of hydrogen concentrations below the ceiling. Results show that hydrogen concentration decreases rapidly within a range of 0.5-1.0m below the ceiling and more gradually from 1.0-2.0m. Additionally, the study explores the radial distribution pattern of hydrogen concentration from the hydrogen jet under the ceiling. By applying a Gaussian model and incorporating an impact reflux term, the researchers refined the predictive formula to enhance the accuracy of monitoring hydrogen leaks in confined spaces. Keywords such as hydrogen leakage, confined space, concentration distribution pattern, hydrogen detection, and FCV safety are discussed in the study. The findings contribute to advancements in sensor technology for better safety measures in facilities handling hydrogen, particularly in improving the detection and monitoring of hydrogen leaks in confined areas.