The invention relates to the technical field of fire prevention and maintenance and discloses a building fire risk real-time dynamic quantitative evaluation method based on the Internet of Things. Inan initial evaluation phase, various site types of social units are classified in a standardized mode, 14 different site models such as a market, an all-in-one site, an industrial enterprise, a publicentertainment site, a group rental house, a hotel, a high-rise building, a hospital, a nursing home, a school, a kindergarten, a construction site, a cultural relic building and a subway are divided,and an index system of each site model is established. A necessary support tool is provided for social units to meet the requirements of national competent departments on three autonomy, two publications and one commitment. A real risk index basis is provided according to the requirements that the commitment field does not have prominent risks or preventive measures have been implemented. A n innovative means is provided for forming an innovative emergency management mode taking a dynamically quantified risk index as a control target.