Coastal nuclear power plants in various countries due to the invasion of Marine organisms caused by nuclear power plant cooling water clogging events frequently occur. Monitoring Marine organisms in the vicinity of nuclear power plants can realize the early warning of the outbreak of disasters, provide conditions for early intervention and early response, and improve the active defense capability of nuclear power plants. This paper reviews the requirements and suggestions for monitoring and early warning in the cold source management regulations and standards, and reviews the Marine biological characteristics of different nuclear power plant sites along the coast of China and the shortcomings of existing monitoring and early warning. This paper proposes a solution which includes a monitoring and early warning platform with diversified monitoring means, rich information and an independent cold source management control room, and provides a reference for the research of cold source monitoring and early warning system for nuclear power plants.