In this article, H∞ /μ controller is relied on to control the power system stabilizer(PSS) using state space approach for a single machine infinite bus (SMIB) system. Design a robust feedback controller for the system using the H∞/μ technology supported by the Matlab / Simulink. The H∞/μ design method leads to a robust controller with a fixed structure and fixed parameters. The uncertainties of the model are taken into account when specifying the weights. The controller demeanor obtained was analyzed through the input represented by the step response and the output response of the power system (PS) in the case of normal operation and then the system with changed parameters. The suggested controller proved its effectiveness by maintaining the stability of the system with acceptable limits of disturbances.