Radioactive substance monitoring and early warning method and police affair monitoring and early warning device

The invention discloses a radioactive substance monitoring and early warning method, which comprises the following steps of: analyzing the danger level of an originating event in a public place to obtain the danger level of a radioactive substance; according to the passenger flow volume and the evacuation distance of the public place, performing calculation to obtain a failure mode and effect analysis of the event; determining the disaster-causing level of the radioactive substance according to the danger level, the failure mode and the effect; disaster reduction factor analysis under human factors is carried out according to response strength deployment and disposal capability in the public place; calculating the risk value of the radioactive substance in the public place according to the disaster-causing level and the disaster reduction factor; and performing early warning according to the risk value. The radioactive article monitoring and early warning method can effectively solve the problem that the curr