<p>In the control of permanent magnet synchronous motor (PMSM) drives, the system is susceptible to various stochastic disturbances, such as sensor measurement noise, electromagnetic interference, power supply fluctuations, and mechanical vibrations. These disturbances can degrade the tracking accuracy of speed and current responses and exacerbate chattering amplitudes within the PMSM drive control system. To address this challenge, this paper proposes a composite optimal control strategy for both current and speed, building upon the foundation of vector control (VC). First, an extended state-space model incorporating stochastic noise is formulated based on the PMSM mathematical model and a load torque compensator is designed to mitigate the disturbance caused by load torque on the state space. Colored noise is then handled using the measurement augmentation method, yielding an extended state-space model that accounts for correlations between state noise and measurement noise. Subsequently, a modified Kalman filter (KF) observer is designed to obtain estimated state values. Finally, leveraging optimal control theory, a state feedback controller is synthesized, and an improved sine cosine algorithm (ISCA) is employed to select appropriate noise covariance matrices. Comprehensive simulation and experimental results demonstrate that the proposed optimal control strategy effectively enhances the tracking precision of both current and speed while significantly improving the disturbance-rejection capability of the control system.</p>