The invention provides a horizontal double-layer buried
storage tank used for storing LNG. The
storage tank comprises an outer container which can completely be buried underground, an inner container arranged inside the outer container, a pump
sump arranged at a vacuum insulation interlayer between the outer container and the inner container, an immersed pump disposed at the bottom inside the pump
sump, a drain
pipe connected with a liquid outlet of the immersed pump, a pump-back air-
pipe and a bottom communicating
pipe communicating the lower part of the pump
sump and the bottom of the inner container. The upper end portion of the pump sump extends out of the top of the outer container. An
imbibition port of the immersed pump is lower than the bottom end portion of the inner container. According to the invention, the pump sump, the immersed pump and the tank body are integrated as a whole, and the
whole body can be buried underground. There is no need to specially build
thermal insulation facilities such as a cryogenic pump sump and the like. Therefore, a lot of manpower, material and financial resources are saved, and it is energy saving and
environmentally friendly to use the horizontal double-layer buried
storage tank.