Abstract: The paper present the application of water cyclone in milling-grading and sulfur-dressing of tailings.The practical results show: the grading efficiency of water cyclone in milling-grading is better than the efficiency of spiral classifier; the dressing targets in sulfur-dressing of tailings by water cyclone are: the sulfur content in sulfur concentrate is 31.22%~40.36%, the recovery is 38.92%~65.43%.Although the grade and recovery of sulfur concentrate fluctuate greatly, yet the process possess with some characteristics such as: operating easily, occupying a little place and low productive costs.This is a main process to recover sulfur of copper ore at present.