1. A positioning control method, suitable for an electronic device mounted on a moving vehicle, the electronic device comprising an image-capturing module and a satellite-based positioning module, the positioning control method comprising steps of: capturing a first image; extracting an icon object from the first image; capturing a second image; identifying the corresponding icon object in the second image; calculating a separation distance between the electronic device and the icon object according to a variance of the icon object between the first and the second images and a displacement distance of the moving vehicle; searching a point-of-interest (POI) site corresponding to the icon object from a point-of-interest database; and calculating or calibrating positioning data of the electronic device according to the separation distance and known coordinates of the point-of-interest site.