The composition and control mode of space optical communication and tracking systems are analyzed, and the source of time lag in the fine tracking control process is summarized. Furthermore, the influence of the time lag link of a fine tracking system on the final tracking accuracy and stability is analyzed, and the precision of fine tracking is improved via system optimization. Initially, the time lag of the fine tracking system is streamlined by optimizing the program processing logic without losing the system function. This in turn eliminates the variable-length time lag and reduces the fixed-length time lag to shorten the time lag of the fine tracking system. Based on this, a robust prognostic control algorithm is proposed to reduce the adverse effect of the fixed-length time lag on the fine tracking system. The final results show that the tracking error of the fine tracking system is reduced from 4.1 μrad to 2.3 μrad after streamlining the time lag link when compared with the original system, and the tracking error is reduced from 4.1 μrad to 2.6 μrad after using the robust prediction control algorithm in the presence of the matching delay error. Additionally, the tracking accuracy of the system is improved by 43.9% and 36.6%, respectively. The tracking accuracy of fine tracking is as high as 1.9 μrad when the robust prognostic control algorithm is tested in the fine tracking system.