Polydisperse gas-particle flow is often encountered in industry and many polydisperse drag models have been developed in literature. In this work, discrete particle method was employed to assess polydisperse drag models for the segregation and mixing of binary gas-particle flow in a bubbling fluidized bed. The degree of particle segregation and the characteristic bubble frequency using different polydisperse drag models were analyzed. It was shown that the results predicted by the model of Rong et al. (2014) are in a best agreement with experimental data with 5.3% errors on average, and two dominant bubble frequencies were found by analyzing the fluctuations of average particle height.