The present invention discloses a method for realizing a unique service for a prepaid service user. The method is used for a base station controller, a mobile switching center and a mobile communication system of a service control point. The method comprises that step one, after receiving an outgoing call application of a terminal user, the mobile switching center sends a service request message to the service control point, the service control point performs corresponding service operation according to the service request message, and sends a service operation result response message to the mobile switching center; step two, after receiving the service operation result response message, the mobile switching center sends the service operation result to the base station controller through flickering the request message, and the base station controller sends the service operation result to the terminal user. The present invention also discloses a device for applying the method for realizing the unique service for the prepaid service user, and a mobile communication system for applying the method and the device.