Coastal zones act as pivotal land-sea interaction zones that generate over half of the global economic output and sustain dense human settlements. The sustainable governance of coastal zones has persistently remained a central topic in international ocean governance. Integrated coastal management (ICM) adopts an integrated approach to formulate and implement environmental protection and sustainable development programs for coastal resources. Simultaneously, marine spatial planning (MSP) is an effective marine management tool for regulating human activity and resolving conflicts over the use of the sea. The interrelationship between ICM and MSP has always been a key issue in the governance of oceans and coastal zones. This study compares and analyzes the compatibility of different ocean management models to MSP from the perspective of management scope, focus, and authority and analyzes the case of Xiamen, where MSP was implemented within the ICM framework. The results show that ICM establishes a robust foundation for the practical implementation of MSP through four dimensions: legislative guarantees, law enforcement systems, cross-departmental coordination, and scientific and technological support. In return, MSP improves the implementation efficiency of ICM through holistic spatial coordination and marine-use conflict resolution. This paper elaborates how the coupling of the two instruments alleviates conflicts over marine resource utilization, restores coastal ecosystems, and fosters high-quality development of the marine economy. The results provide insights for developing theoretical and practical applications of sustainable management in marine and coastal zones.