The invention discloses a purification and rectification process of sulfur tetrafluoride. The preparation process of sulfur hexafluoride is controlled through inductance elements. The process is carried out by using the following devices: a weighing device, a containing box, a quantitative valve, a sulfur tetrafluoride reactor, a stirrer, temperature sensors, a pressure sensor, an air pump, a cooler, a condensation catcher and a rectification tower. The process comprises the following operation steps: proportioning raw materials, preparing sulfur tetrafluoride, cooling crude gas, purifying thecrude gas and rectifying sulfur tetrafluoride. According to the invention, the condensation temperatures of the temperature control cooler and the condensation catcher are measured by the temperaturesensors, so that preparation of the sulfur tetrafluoride product is facilitated; and pressure in the sulfur tetrafluoride reactor is measured through the pressure sensor, so that scientific export ofthe crude gas is facilitated. The electric appliance elements used in the process do not need manual operation, the effect of full-automatic operation is achieved, the error of preparing the sulfur tetrafluoride product is reduced, purification precision is improved, and the purification precision is improved by 37% compared with purification precision of manual operation.