Abstract: The characteristics of safety monitoring for artificial islands in coastal areas during the operation stage are systematically analyzed. The relevant monitoring items are determined. The first automatic safety monitoring system for the artificial islands in coastal areas in China has been developed. The warning indices and modes for the safety monitoring of the artificial islands in coastal areas during the operation stage are put forward. The warning for the safety of the artificial islands in coastal areas during the operation stage includes the following two aspects: warning of design environment and warning of safety monitoring of islands. The warning indices include the horizontal displacement and settlement of embankments. The warning modes are hierarchical ones according to the variation of monitoring data, deposition and erosion in sea areas, shallow cutting of sections and stability analysis of slopes. The relevant countermeasures for the engineering safety are put forward so as to provide the technical basis and support for the safe construction and management of the artificial islands in coastal areas during the operation stage.