This paper presents an optimization study on self-evaporation vapor cooled shield (VCS) in liquid hydrogen (LH2) storage tank with multilayer insulation (MLI). Production from other clean energy sources (such as solar energy, wind energy and biomass energy) and combustion without pollution make H-2 a promising renewable energy source to reduce air pollution and greenhouse effect. Due to the advantages of low pressure and high energy density, LH2 storage has broad prospects in aerospace and civil market. Because of low critical temperature and volatility, LH2 tank poses severe requirements to MLI. In order to reduce heat leak into tank, VCS was set up to cool MLI by retrieving the sensible heat of discharged cryogenic gas hydrogen (GH(2)). In this study, a simplified thermodynamic model is established to investigate the optimal position of VCS in MLI, and the effect of VCS on heat leak into tank and temperature profile through MLI has been studied. Compared with heat leak without VCS, the maximum decrease with Single-VCS is 50.16% and Double-VCS by 59.44%. VCS can also play a positive role under the condition of vacuum failure, and its inhibiting the sharp increase of heat leak is of great significance in emergencies.