Abstract: Liquid hydrogen is prone to form gas-liquid two-phase flow during pipeline transportation, which seriously affects the safety and efficiency of the system. To address this problem, this paper establishes a three-dimensional numerical model of the liquid hydrogen pipeline, to analyze the main heat transfer processes, and optimize the form of support and pipeline joint. At the same time, the flow characteristics of the liquid hydrogen pipeline are investigated, and the influence of process parameters such as inlet flow rate, pressure on the gas holdup and temperature increase of the liquid hydrogen pipeline cross-section is analyzed. The results show that the triangular support and Bayonet joints have the best insulation effect. During the transportation of liquid hydrogen, the gas holdup of the pipeline cross-section decreases and then increases with the increase of inlet flow rate. The optimum inlet flow rate for a liquid hydrogen pipeline with a diameter of Φ32 mm is 4 m/s. An increase in the inlet pressure of liquid hydrogen reduces the gas holdup of the cross-section and can effectively reduce the temperature rise of liquid hydrogen. Reasonable inlet flow rates and pressures should be determined iniquid hydrogen pipeline process design and engineering applications to ensure safe and efficient operation of the liquid hydrogen transportation system.