In order to separate, recycle and second thresh the no cleaned pod effectively, the Fluent software was used for optimization analysis of two different models of cyclone separator with or without bucket. The simulation results showed that there was no significant difference in pressure drop between the two models, cyclone with bucket had higher separation efficiency. Effect of bucket diameter and length on the capture time was not significant. The mathematical relationship model was established between bucket length, diameter and escape time, loss rate and pressure drop. Bucket diameter mainly affected velocity of spiral flow, and bucket length mainly affected the air flow distribution of entrance field. The best parameters of bucket were determined, i.e., the bucket length was 94mm and diameter was 196mm. Test was carried out to verify the improved model based on these parameters, and results showed that the loss rate was reduced to 2.2%.