The utility model relates to a whirlpool gas purifying separating device which belongs to a heat engineering energy saving device. The utility model has a gas separating part and a gas purifying part, which comprises a laval nozzle 1, a hydrocyclone 2, a separating tube 3 connected with the hydrocyclone, a pressure enlarging tube 4, an outer shell body 5 used for connecting a spraying tube with the hydrocyclone and a pressure enlarging tube shell body 6 connected with the separating tube. The middle part of the device is provided with the hydrocyclone and the separating tube, wherein the hydrocyclone is fixed to the inner cavity of a hydrocyclone shell body connected with one end of the spraying tube of which the other end is provided with a gas inlet 10; the separating tube is communicated with the pressure enlarging tube of which the other end is provided with a dry gas outlet 11, and the lower end part of the pressure enlarging tube shell body is provided with a liquid outlet 12 separated from gas. The gas speed increase process, the temperature fall process, the gas speed reduction process and the voltage increase process of the utility model are respectively completed in the spraying tube and the pressure enlarging tube, the gas purifying process and the separating process are completed in the hydrocyclone and the separating tube and all the processes do not need to consume any mechanical work. The utility model which is suitable for a remote area or an area with a bad environment has the characteristics of favorable purifying separating effect, low comprehensive cost, etc.