Household security is a specific application in intelligent building, which is of great significance to people, particularly to the aged and children. This paper applied networking technologies to household safety, adopting RFID to mark the hazard source of the houses of the aged and the children, and set up different risk factors for disparity ages. It designed a safety household prototype system, using fuzzy reasoning method. And made a hazard identification and risk analysis toward the achieved information. Finally, provide a corresponding level of hazard warning, according to the risk coefficient.