Flood control decision-making is an intellectualized decision process. The agent is an important technology in artificial intelligence. A flood control decision-making model constructed by dint of an agent is able to decompose the complexity of flood control decision process, and the abstract makes the agent being able to accomplish the different functions. According to the effects, the agent may have three types of protocol agent, mission agent and model agent. Mutual cooperation makes the accomplishment of flood control decision process feasible. This paper takes the flood forecasting system as an example, and explains the advantages of the flood control decision-making model based on the agent.