The invention relates to a gas cylinder for a liquefied natural gas. The gas cylinder comprises an outer cylinder and an inner container, wherein a central hole wall at the left end of the outer cylinder is welded to one end of a left connecting tube, the other end of the left connecting tube is welded to a left connecting joint, the left connecting joint is fixed with an epoxy sleeve, a right connecting joint is further fixed on the epoxy sleeve, the right connecting joint is welded to one end of the right connecting tube, the other end of the right connecting tube is welded to one end of an inner large connecting tube by virtue of a choke plug, the other end of the inner large connecting tube is welded to the central hole wall at the left end of the inner container, the left connecting tube and the right connecting joint are sleeved in the epoxy sleeve, the epoxy sleeve is idly sleeved in the inner large connecting tube; the center in the right end of the inner container is welded to a supporting shaft, the left end of the supporting shaft is welded to a tubular cap, the tubular cap is fixed to the inner container by welding, the right end of the supporting shaft extends out of a reinforcing plate, the supporting shaft between the supporting shaft and the reinforcing plate tightly sleeves the epoxy steel supporting sleeve, the epoxy steel supporting sleeve is externally and tightly sleeved with a stainless steel sleeve ring, and the stainless steel sleeve ring is fixed with the reinforcing plate by welding. The gas cylinder for the liquefied natural gas is simple to assemble and manufacture, and low in heat transfer rate.