In recent years, the demand of Large LNG storage tank increases over time, but large LNG cryogenic storage tank has not yet established a series of standards and norms, and tank construction technology is also lagging behind. Aiming at the design of the tank form a single, smaller, did not tackle the issue of, this paper mainly discusses from Large LNG tanks, such as type, material selection, structure ,size optimization and so on, which can provide reference for independent construction of storage tank.