Abstract: The abnormal fluctuations of feed pressure and density of medium suspension of the 3-product heavy medium cyclone exert a great impact on the normal operation of the heavy medium separation system. To address the issue, a study is made on the laws governing the variations of the aforesaid two parameters. Through the application of a fault early warning system and adoption of corresponding measures based on analysis of types of faults, it is possible to realize detection and treatment of any fault in a timely manner. Practice shows that the application of the early warning system has led to the creation of direct economic revenues of 2.941 6 million yuan per year and reduced labor intensity for fault handling work, yielding as a result a noticeably favorable composite economic result.