The invention provides a process and a device for drying gas in order to achieve the zero release and mainly solve the problems of environmental pollution caused by directly releasing the gas in a regeneration tower, or waste caused by the combustion of the gas and high cost in the process for pressure-reduction regeneration in the prior art. The process of the invention comprises three links of absorption, regeneration and switching, wherein the dried finished gas as the regenerated heating gas and blast-cold gas in regeneration can be subjected to adsorbent regeneration at lower heating temperature to obtain the finished gas having low dew-point temperature and further returned to the process of absorption, thus allowing no gas to be released to the atmosphere and achieving the real zero release.