This article introduces the classic locating method based on the receiving signal strength in the cognitive radio and puts forward a cognitive radio-receiving signal strength(CR-RSS) localization algorithm which solves the problem of secondary users locating the primary user and succeeds in estimating the primary user’s location and transmission power. Through the establishment of cognitive radio network, evaluating the number of secondary users,sampling and the environmental factors to the results in CR-RSS approach. The consequence shows that this approach can effectively locate the primary user and the technology of localization in cognitive radio can assist network optimization. This article introduces the classic locating method based on the receiving signal strength in the cognitive radio and puts forward a cognitive radio-receiving signal strength (CR-RSS) localization algorithm which solves the problem of secondary users locating the primary user and succeeds in estimating the Through the establishment of cognitive radio network, evaluating the number of secondary users, sampling and the environmental factors to the results in CR-RSS approach. The results shows that this approach can effectively locate the primary user and the technology of localization in cognitive radio can assist network optimization.