LNG storage tank insulation system having welded secondary barrier and construction method thereof

Disclosed herein is a Liquefied Natural Gas (LNG) storage/transportation tank insulation system having a welded secondary barrier and a construction method thereof. The LNG storage/transportation tank insulation system is configured such that a plurality of secondary insulation panels, which is continuously mounted to be connected to a hull, is connected to the hull using coupling means, a secondary barrier is integrally formed on the secondary insulation panels by welding strakes, each of which is formed by processing a thin metal sheet, primary insulation panels are bonded to and mounted onthe secondary insulation panels using adhesive layers so that the primary insulation panels are staggered with the secondary insulation panels, after the adhesive layers are formed on the secondary barrier, and a primary barrier is mounted on the primary insulation panels, which are welded.