The present invention is related to method and device for building Wi-Fi radio map. Especially, it is related to device and method for building Wi-Fi radio map that is used to position locating service that utilizes Wi-Fi fingerprints that many, unspecified mobile terminals collect and provide. Specifically, the present invention provides, as methods for estimating position data for AP (200) using Wi-Fi fingerprints collected by mobile terminals (100), 1) method for estimating position data for AP (200) by linking Wi-Fi fingerprints and time data for collecting Wi-Fi signal, or 2) method for estimating position data for AP (200) through user address data comparison between Wi-Fi fingerprints without linking signal collection time data to Wi-Fi fingerprints. Accordingly, it has effects of epoch-making economic feasibility compared to prior art that requires huge cost in collecting Wi-Fi fingerprint like war driving.