[目的]为提高车载液氢储运安全性，揭示车载液氢泄漏扩散特性，[方法]建立典型非空旷区液氢储罐泄漏仿真模型，研究了运输过程中液氢泄漏扩散行为，分析了不同场景空间下氢气云团体积和分布范围。[结果]液氢泄漏区域的空间结构对氢气扩散轨迹影响极大；建筑区气流阻滞效应导致氢气紧贴建筑墙壁向上和两侧绕行，虽然改变氢气扩散轨迹并抑制其大范围扩散，但建筑周围氢气存留时间延长使得危险程度增加；半封闭的隧道内氢气受浮力驱动撞击顶壁后呈“降落伞”状积聚，形成稳定的顶部高浓度分层并沿纵向缓慢层流扩散；地下车库的泄漏氢气呈“蘑菇状”迅速上升并向四周填充，因通风条件差，可燃气云体积增长最快，发生燃爆潜在风险显著升高。研究成果可为车载液氢安全输送技术和智能管控提供理论依据。

In order to improve the safety of vehicle-mounted liquid hydrogen storage and transportation, and reveal the leakage and diffusion characteristics of vehicle-mounted liquid hydrogen, a numerical simulation model was established to study the leakage and diffusion behavior of liquid hydrogen during transportation. The volume and distribution range of hydrogen clouds in different scene spaces were analyzed. The results show that the spatial structure of the liquid hydrogen leakage area has a significant effect on the diffusion trajectory of hydrogen gas. The airflow blocking effect in the building area causes hydrogen to closely adhere to the building walls and circulate upwards and on both sides. Although it changes the diffusion trajectory of hydrogen and inhibits its large-scale diffusion, the prolonged retention time of hydrogen around the building increases the level of danger. The hydrogen gas inside the semi enclosed tunnel is driven by buoyancy and collides with the top wall, accumulating in a "parachute" shape, forming a stable high concentration layer at the top and slowly diffusing in laminar flow along the longitudinal direction. The leaked hydrogen gas in the underground garage rises rapidly in a mushroom shape and fills the surroundings. Due to poor ventilation conditions, the volume of combustible gas clouds grows the fastest, and the potential risk of explosion significantly increases. Those results can provide theoretical basis for the safe transportation technology and intelligent control of liquid hydrogen in vehicles.