The invention provides a tobacco material classifying device and classifying method. The equipment comprises a winnowing box machine body, a tangential material discharging device and a classifying filtering mesh belt; the top of the winnowing box machine body is connected with the tangential material discharging device; the classifying filtering mesh belt is located on the upper portion of the winnowing box machine body, penetrates into one side of the winnowing box machine body and penetrates out of the other side of the winnowing box machine body; after the classifying filtering mesh belt penetrates out of the winnowing box machine body, a conveying device is arranged under the classifying filtering mesh belt. According to the tobacco material classifying device and method, materials move upwards through wind power, sundries fall into a sundry falling area due to the fact that the self gravity is larger than the wind power, cut rolled stems float and move upwards to a filter area, pass through the classifying filtering mesh belt and then collected and output, and flaky cut rolled stems are attached to the lower surface of the classifying filtering mesh belt, are taken out of the winnowing box machine body by the classifying filtering mesh belt, fall into the conveying device and then are discharged. Therefore, continuous, steady and uniform material classification is achieved, the defects that a traditional vibrating screen classifier is high in tobacco damage ratio, low in classification rate and the like are overcome, and the classification and usage requirements for different cut rolled stem forms in cigarette processing can be met.