In the TCP/AQM network system, the data transmission process of the ship shore communication system was affected by the long distance and the storage and forwarding mechanism, resulting in time delay. The output queue length of the TCP/AQM network system was caused to exhibit lag, making it difficult for the controller to obtain real-time queue lengths. The effectiveness of congestion control was weakened and queue length oscillations could easily be triggered when lagged queue lengths were used for control. To address the aforementioned issues, a global sliding mode active queue management method based on a delay observer was proposed in this paper. First, a delay observer was designed to predict the output with delay. The predicted state was used as the state variable at the actual time for feedback control, thereby eliminating the delay effect. Subsequently, a TCP/AQM congestion controller was designed using a global sliding surface. The reaching phase in sliding mode control was eliminated by this approach, and robust performance was ensured throughout the entire operation of the TCP/AQM network system. Finally, the results showed that this method significantly enhances both the congestion control stability and data transmission performance of the ship-to-shore communication TCP/AQM network system.