Drying process for thenardite

The invention relates to a drying process for thenardite. The process comprises the following steps of: removing mechanical impurities from original mirabilite liquid with a certain concentration conveyed underground flow by using a pipeline filter and refining and purifying the original mirabilite liquid by using an ion exchanger under the monitoring of a DCS automatic monitoring system and the control of an AK liquid balancing flow meter to obtain refined mirabilite liquid with extremely low impurity content; inputting the refined mirabilite liquid into a continuous crystallizing process system; continuously performing solid-liquid separation by using a first-stage centrifugal machine to obtain mirabilite crystal; and inputting the mirabilite crystal into a multi-stage spiral vacuum drying machine for drying and removing water moisture so as to obtain the thenardite which contains 0.01 to 0.03 percent of free water.