The invention applies to the field of nuclear power safety, and provides a method and a device for controlling people permission in a nuclear power plant area. The method comprises the steps of acquiring request information of entering the nuclear power plant area; determining whether the marking information gains the permission of entering the nuclear power plant area according to an authorization data sheet; if so, searching acceptable people number corresponding to the current mode of the nuclear power plant area; if the current people number of the nuclear power plant area meets the acceptable people number requirement, allowing the requiring people to enter the nuclear power plant area. With the adoption of the method for controlling the people permission in the nuclear power plant area, the people number of the nuclear power plant area can be controlled according to the current mode corresponding to different times, and thus people can be evacuated effectively in emergency, and as a result, the personal safety of workers can be improved.