Abstract: Abstract: For the purpose of ensuring building fire safety, research the key technologies of real-time fire safety monitoring in the context of smart cities. Based on the big data analysis technology, communication technology and cloud computing technology of smart city construction, this technology builds a key technical framework for real-time fire safety monitoring. Using the photoelectric smoke detector and temperature sensor in the sensing layer of this framework, smoke data and temperature data in urban public buildings are collected, and then transmitted to the cloud computing layer using the communication layer; The fire safety monitoring and early warning module in the cloud computing layer uses the fuzzy Bayesian network in big data analysis technology to assess the current fire risk degree of urban public buildings, and realizes real-time fire safety monitoring and early warning based on the assessment results. Then, through the fire safety risk area positioning module, the sensor centroid algorithm is used to obtain the location of the building fire safety risk area, and the fire safety real-time monitoring, early warning and fire safety risk area positioning are transmitted to the exhibition floor for display. The experiment shows that this technology can accurately collect the temperature data in the building, accurately detect the fire location, and send a fire alarm before the fire occurs.

Key words: Key words: smart city, fire safety, real-time monitoring technology, bayesian network, positioning method