Driven by ongoing technological advancements, Unmanned Surface Vehicles (USVs) have become essential for modern maritime operations, including military, surveillance, patrol, and environmental monitoring. This review examines key technologies for USV system integration, including operational requirements, payload integration, resource management, and communication and data processing. It also explores reliability, maintainability, and human-machine interaction needs, highlighting how mission system integration enhances operational efficiency, stability, and autonomy. The incorporation of artificial intelligence and deep learning is making USV mission systems increasingly intelligent and adaptable. However, challenges remain in resource optimization, fault detection and fault-tolerant control, and data security. Finally, the review discusses future directions, particularly breakthroughs in intelligent decision-making, multi-task collaboration, and system security.