Abstract: In industrial process operation, the purpose of control is to achieve the desired technique indices (TIs) which represent the performance of process operation. In this paper, an extended decoupling internal model control (IMC) method for optimal operation of industrial process is proposed. Via designing a generalized internal model controller, a control loop setting model is obtained, which has characteristics of high dimension decoupling, good robust stability and strong disturbance rejection. This setting model can auto-adjust the setpoints of lower level controllers in response to process uncertainties and disturbances. As long as the outputs of the basic loop track their adjusted setpoints, the desired TIs are achieved. An application in grinding circuit and several simulation studies are presented to demonstrate the proposed control approach.