The present invention discloses a method and an apparatus for localization and mapping based on color block tags, applicable for real-time mapping of an area to be localized in which at least one color block tag is arranged, the method comprises: taking a location of a first color block tag as a coordinate origin of a coordinate system when information of the first color block tag is obtained by a mobile electronic device; moving the mobile electronic device to start to traverse the entire area to be localized from the coordinate origin, calculating coordinates of an obstacle detected by the mobile electronic device based on a location of the mobile electronic device relative to the coordinate origin; constructing a map based on recorded information of the color block tags and coordinates thereof and the coordinates of each obstacle when the traversal has been finished.