Abstract: With an aim to achieving an improved washing effect of the heavy medium cyclone, the entire washing system is restructured using the interactive design engineering analysis software (IDEAS)and dynamically simulated with the raw coal property, medium suspension characteristic data, cyclone′s structural parameters and external operating conditions as the initial parameters, to verify the reliability of the model selected and the accuracy of the initial parameters. Following optimization of the existing system using the selected model and the verified initial parameters, the content of the renovation work to be made for further optimization of the system is thus defined. Practice shows the renovated system can operate with its all performance indices well up to the desired requirements; the ash of the clean coal and the loss of coal in middlings and rejects are lowered to 10.36%, 7.17% and 2.86% respectively; and the system works with an overall organic efficiency of 92.19% with the E_pm values of its first and second stages being 0.050 g/cm³ and 0.055 g/cm³, respectively. The use of the renovated system makes it possible for the plant to gain an additional clean coal production capacity of 24.96 thousand tons, bringing about a noticeably favorable economic result.