To improve the efficiency of cross-regional environmental integrated and coordinated management, protect the limited water resources and avoid the transboundary water pollution caused by environmental disputes, the current situations of cross-border region water environmental information sharing and opening are analyzed. From the four aspects of water environmental information content, water environmental information sharing ideas, transfer mode and sharing system, the regional water environmental information sharing mechanism are established. The cross regional water environmental information sharing system is an important part of national basic information resources, which enhances the emergency response capability of regional environmental supervision, and expands the public's right to know and the right to participate in environmental issues.