The present invention provides a device for determining whether a target object effectively enters a specified geographic area. The device comprises a data acquisition module, an analysis calculation module and a judgment module; the data acquisition module is used for periodically acquiring the real-time position data of an object; the analysis calculation module is used for calculating the number of the intersection points of a straight line between the current location of the object and the last-time location of the object and a specified first continuous closed region and a second continuous closed region in a coordinate reference system based on the location of the real-time position data which are obtained currently and the location of real-time position data which are obtained the last time in the coordinate reference system; and the judgment module is used for determining whether the object effectively enters or exits from the first continuous closed region according to the number of the intersection points. According to the device of the invention, the second continuous closed region is set outside the specified geographic area, so that the difference of real-time position data sent by a location data sending device and an actual location can be avoided, and the condition of the specified geographic area can be determined, a data analysis result is closer to an actual result, and accuracy can be improved.