The invention belongs to the application field of gas adsorption and separation, in particular to a rare gas adsorption and trapping device and its adsorption and trapping process and application. Including shell, forward air intake pipeline, forward exhaust pipeline, reverse exhaust pipeline, adsorber is placed in the shell, the adsorber is a radial flow or axial flow adsorption bed, and the adsorber has built-in adsorbent and heat exchange Assemblies, the cooling / heating medium pipeline I and the cooling / heating medium pipeline II are arranged on both sides of the shell. The adsorbent is a high thermal conductivity adsorbent, and the high thermal conductivity adsorbent is a mixture of a porous material and a thermal conductivity agent. Through the operation process of raw material gas adsorption and cooling, raw material gas pressure boost, forward adsorption, forward decompression and exhaust, temperature rise and reverse vacuum desorption, the components in the raw material gas are adsorbed and separated. The thin gas adsorption and trapping device provided by the invention has short process flow, strong raw material gas adaptability, and high concentration multiple, which solves the problems of low efficiency and long cycle in the existing thin gas concentration detection and rapid purification of toxic and harmful gases.