Abstract: Aiming at the demand of low heat leakage of the cryogenic liquid hydrogen storage tank of the high-altitude long-flight UAV, the arrangement of the vapor-cooled shield of the UAV liquid hydrogen storage tank is studied, the heat transfer process through the adiabatic structure is analyzed, the heat transfer model of the adiabatic structure is established to predict and optimize the thermal performance of the composite adiabatic structure. Given the characteristics of hydrogen and the structure of the cryogenic tank, the optimal position and quantity of the Vapor-Cooled Shield （VCS） of the cryogenic liquid hydrogen storage tank and the reduced heat leakage of the VCS are parameterized under specific storage temperature and pressure. The results show that compared with the insulation structure without VCS, the heat leakage of the liquid hydrogen （LH₂） tank can be reduced by 59.10% with one VCS. The best position of the single VCS is in the middle of Spray-on Foam Insulation （SOFI）. The heat leakage is lower when multiple VCSs are set in series within SOFI. Considering the limitation of the total weight of the storage tank, it is better to set two VCSs in series within SOFI. The insulation performance of the storage tank is the best when the two cold screens are located near the three-equal position of SOFI.