Abstract: Aiming at the phenomenon of successively poor effect of multi-cycles chemical profile control technology, by the use of visualization and plate models, the mechanism of its poor effect has been analyzed and concluded. Based on the mechanism analysis and physical simulation, the conclusion finds that with the increasing multi-cycles, the intensity will be enhanced accordingly. With the application of numerical simulation technology, the optimal timing and volume of profile control have been determined. After 3 cycles profile control in 5 water injection wells, the injection pressure of the average single well increased from 10.7 MPa to 13.1 MPa and the water cut of the connected oil wells decreased by 9.2%.