Discrete element method (DEM) has been used to study the effect of process parameters, filling ratio, impeller speed, and vessel speed, on granular mixing performance in an intensive mixer. Their effects were evaluated in terms of coordination number (CN), relative standard deviation at a specified time (RSDT) and relative standard deviation at a specified input work (RSDIW). Analysis of variance (ANOVA) and response surface method (RSM) were employed to study the significance analysis of the individual factor effects and factor combination. The results of experiments indicate that CN and RSDT increase with the increase of filling rate and the decrease of impeller speed, and RSDIW increases with the increase of filling rate, while the influence of vessel speed and impeller speed on RSDIW is dependent on the other two parameters of mixer. Additionally, filling rate, impeller speed and vessel speed showed interactive effects on all presented responses. ? 2021 Elsevier B.V. All rights reserved. Discrete element method (DEM) has been used to study the effect of process parameters, filling ratio, impeller speed, and vessel speed, on granular mixing performance in an intensive mixer. Their effects were evaluated in terms of coordination number (CN), relative standard deviation at a specified time (RSDT) and relative standard deviation at a specified input work (RSDIW). Analysis of variance (ANOVA) and response surface method (RSM) were employed to study the significance analysis of the individual factor effects and factor combination. The results of experiments indicate that CN and RSDT increase with the increase of filling rate and the decrease of impeller speed, and RSDIW increases with the increase of filling rate, while the influence of vessel speed and impeller speed on RSDIW is dependent on the other two parameters of mixer. Additionally, filling rate, impeller speed and vessel speed showed interactive effects on all presented responses.