The article focuses on the importance of ensuring the safe transportation of hydrogen, especially through natural gas hydrogen mixing technology in urban areas. With the construction of underground pipe galleries becoming more prevalent in developing cities, there is a need to understand the leakage and diffusion characteristics of hydrogen-doped natural gas pipelines passing through these structures. Various studies have been conducted to analyze the behavior of hydrogen-doped natural gas in confined environments, leakage rates, and the impact of different factors on gas diffusion. Researchers have also looked into the influence of wind speed, leakage direction, and hydrogen volume concentration on the diffusion of gas in valve chambers and underground pipeline corridors. While some scholars have studied gas leakage and diffusion in public pipe corridors, there is still a gap in understanding the behavior of hydrogen-doped natural gas in long and narrow underground structures like pipe corridors. The article introduces a numerical model to analyze concentration distribution and velocity fields of hydrogen-doped natural gas under different conditions. Additionally, a backpropagation neural network prediction method is proposed to assess the explosion risk volume of methane and hydrogen in various scenarios. This method aims to provide reliable information for safety design and improve risk assessment in urban pipe corridors to enhance the safety of hydrogen transportation.