This paper proposes an enhanced inverse decoupling-based direct yaw moment control (ID-DYMC) method for a four-wheel independent steering mobile robot (FISMR), realizing the coordinated regulation of the sideslip angle and yaw rate. In contrast with the traditional coupling control schemes, which may usually lead to the vibration of yaw moment, our method is capable of stabilizing the resulted decoupled system and improving the steering maneuverability. At first, the sideslip angle and rate yaw rate are derived separately by establishing a general dynamic formula. Then, to accommodate the coupling between the state variables, the inverse system decoupling control method is presented. Through the integration of the inverse feedback variables of the FISMR, the multiple single-input single-output subsystems are constructed, which are controlled by the adaptive fuzzy sliding mode controller individually. With real-life experiments, it is concluded that the proposed ID-DYMC method can be effectively applied to the yaw moment control of the considered FISMR.