The utility model discloses a novel case lid based on high low temperature post case, outer cap and inner bag lid including its lower extreme flushes and upper portion is connected are present in the clearance between each side of outer cap and inner bag lid, are packed fullly by thermal insulation material the insulating layer of the clearance formation between outer cap and the inner bag lid, two pairs of access openings that run through shell caping portion, insulating layer and inner bag caping portion to and three at least the setting in the hasp of outer cap side, wherein, with surrounding the equipartition the lower extreme department of flushing of insulating layer packing to outer cap and inner bag lid flushes. The utility model discloses the double -deck heat insulation system of lid structure inside and outside utilizing adopts the insulating layer of thermal insulation material filling effectively to keep warm to the inner bag lid is interior, helps the accurate control of high low temperature post incasement temperature, and the dedicated pore of simultaneous design is connected with complete network devices such as chromatographic detector and liquid nitrogen transmission pipes, and is with strong points.