The invention is applicable to the field of nuclear power technology and provides a method and device for handling a nuclear power accident. The method for handling the nuclear power accident includesthe steps of obtaining affected information of a fire compartment in the event of a fire; analyzing redundant information and alternative information of the affected information, and determining themanner of disposal of the affected information based on an analysis result; saving the affected information and corresponding manner of disposal thereof to an accident handling list; if a fire in thefire compartment is detected, obtaining a current accident handling stage of the fire compartment; and according to the accident handling stage and the accident handling list, outputting accident handling guidance information for the fire compartment. According to the invention, an operator is allowed to correctly diagnose the state of a unit according to the accident handling guidance informationin the event of a fire and avoid possible misdirected risks, so that the operator can be ensured to use a correct accident handling sequence to control the unit and guide the withdrawal of the unit or stabilize the unit in a safety state, and thus the fire safety level of nuclear power plants is increased.