Composite polyether is a raw material system of polyurethane foam, which is mainly composed of polyether polyols, catalysts, foaming agents, foam stabilizers and other components. Composite polyethers for shell-and-tube LNG (liquefied natural gas) have good thermal insulation properties, and they are able to form polyurethane foams with high cell closure. The closed-cell structure effectively blocks the transfer of heat, which is critical for cryogenic storage and transportation of LNG, which needs to be stored at extremely low temperatures (about -162C).