Abstract: With the rapid advancement of laser technology, high-precision tracking of long-distance targets has become increasingly critical in military, aerospace, and autonomous driving applications. To meet the requirements of high accuracy and rapid response, a compact fine-tuning fast steering mirror （FSM） system has been developed. A novel co-grooved flexural hinge structure was constructed to enhance the system's natural frequency while reducing its overall dimensions. Subsequently, dynamic modeling and simulation analysis of the FSM system were conducted in MATLAB. By introducing an innovative optimal control function and nonlinear functions, a linear tracking differentiator and extended state observer （ESO） were designed, resulting in an improved active disturbance rejection control （ADRC） system. Comparative experiments with traditional PID control demonstrate that the enhanced ADRC system exhibits superior performance in suppressing overshoot and oscillation phenomena. Additionally, it achieves a 10.91% improvement in operational bandwidth and reduces phase delay by 2.3 ms, significantly diminishing the impact of disturbance signals. The developed FSM system not only fulfills stringent performance requirements but also demonstrates strong robustness. This work provides valuable insights for the design and optimization of fast steering mirrors, offering important references for precision tracking applications.