In the paper, the status of flood disaster in China and the progress of disaster prevention and reduction in the field of property insurance were analyzed. The characteristics and application fields of 3S (GIS, RS and GPS) were also introduced. According to the current need and future development of property insurance company, which were based on the investigation to the work of disaster prevention and reduction in property insurance and casualty company (abbreviated as PICC) China, the authors decided to apply 3S technologies to the field of property insurance and used the successful methods in foreign property insurance companies for reference to develop a decision support system of flood disaster for property insurance. The system linked well with the operational system of insurance company and realized seamless integration between different data sources. The work of disaster prevention and reduction in property insurance company was better organized both in theory ways and in key technologies. As a result, the economic benefit of property insurance company was really improved. The system was applied in Shenzhen, China and the result was satisfying