The embodiment of the application discloses a map construction method, and a navigation method and device. An embodiment of the map construction method comprises the following steps: acquiring radar scanning reflection data of a current frame; determining similarity of the current frame and a key frame based on the radar scanning reflection data; in response to a condition that the similarity of the radar scanning reflection data of the current frame and the key frame does not exceed a similarity threshold, determining a location identifier for indicating the location of the current frame; andadding the radar scanning reflection data of the current frame and the location corresponding to the current frame to a radar scanning reflection data set with the determined location identifier, andregarding the current frame as the new key frame. By continuously collecting the radar scanning reflection data, the amount of the radar scanning reflection data under various location identifiers can be updated and enriched, so that the environment representative element can be continuously updated and enriched.